Registration Protocols Extensions

Internet Engineering Task Force (IETF)                         R. Carney
Internet-Draft
Request for Comments: 8748                                  GoDaddy Inc.
Intended status:
Category: Standards Track                                       G. Brown
Expires: April 23, 2020
ISSN: 2070-1721                                     CentralNic Group plc
                                                               J. Frakes
                                                        October 21, 2019
                                                              March 2020

 Registry Fee Extension for the Extensible Provisioning Protocol (EPP)
                     draft-ietf-regext-epp-fees-20

Abstract

   Given the expansion of the DNS namespace, namespace and the proliferation of
   novel business models, it is desirable to provide a method for
   Extensible Provisioning Protocol (EPP) clients to query EPP servers
   for the fees and credits associated with various billable
   transactions and provide expected fees and credits for certain
   commands and objects.  This document describes an EPP extension
   mapping for registry fees.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list  It represents the consensus of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid the IETF community.  It has
   received public review and has been approved for a maximum publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of six months this document, any errata,
   and how to provide feedback on it may be updated, replaced, or obsoleted by other documents obtained at any
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   This Internet-Draft will expire on April 23, 2020.
   https://www.rfc-editor.org/info/rfc8748.

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   Copyright (c) 2019 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Conventions Used in This Document . . . . . . . . . . . .   3
   2.  Migrating to Newer Versions of This Extension . . . . . . . .   4
   3.  Extension Elements  . . . . . . . . . . . . . . . . . . . . .   4
     3.1.  Client Commands . . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Currency Codes  . . . . . . . . . . . . . . . . . . . . .   5
     3.3.  Validity Periods  . . . . . . . . . . . . . . . . . . . .   5
     3.4.  Fees and Credits  . . . . . . . . . . . . . . . . . . . .   6
       3.4.1.  Refunds . . . . . . . . . . . . . . . . . . . . . . .   7
       3.4.2.  Grace Periods . . . . . . . . . . . . . . . . . . . .   7
       3.4.3.  Correlation between Refundability and Grace Periods .   7
       3.4.4.  Applicability . . . . . . . . . . . . . . . . . . . .   7
     3.5.  Account Balance . . . . . . . . . . . . . . . . . . . . .   8
     3.6.  Credit Limit  . . . . . . . . . . . . . . . . . . . . . .   8
     3.7.  Classification of Objects . . . . . . . . . . . . . . . .   9
     3.8.  Phase  "Phase" and Subphase "Subphase" Attributes . . . . . . . . . . . . . .   9
     3.9.  Reason  . . . . . . . . . . . . . . . . . . . . . . . . .  10
   4.  Server Handling of Fee Information  . . . . . . . . . . . . .  11
   5.  EPP Command Mapping . . . . . . . . . . . . . . . . . . . . .  12
     5.1.  EPP Query Commands  . . . . . . . . . . . . . . . . . . .  12
       5.1.1.  EPP <check> Command . . . . . . . . . . . . . . . . .  12
       5.1.2.  EPP Transfer Query Command  . . . . . . . . . . . . .  16
     5.2.  EPP Transform Commands  . . . . . . . . . . . . . . . . .  18
       5.2.1.  EPP <create> Command  . . . . . . . . . . . . . . . .  18
       5.2.2.  EPP <delete> Command  . . . . . . . . . . . . . . . .  20
       5.2.3.  EPP <renew> Command . . . . . . . . . . . . . . . . .  21
       5.2.4.  EPP <transfer> Command  . . . . . . . . . . . . . . .  23
       5.2.5.  EPP <update> Command  . . . . . . . . . . . . . . . .  25
   6.  Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . .  27
     6.1.  Fee Extension Schema  . . . . . . . . . . . . . . . . . .  27
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  32
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  32
     8.1.  XML Namespace . . . . . . . . . . . . . . . . . . . . . .  32
     8.2.  EPP Extension Registry  . . . . . . . . . . . . . . . . .  32
   9.  Implementation Status . . . . . . . . . . . . . . . . . . . .  33
     9.1.  RegistryEngine EPP Service  . . . . . . . . . . . . . . .  33
   10. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  34
   11. Change History  . . . . . . . . . . . . . . . . . . . . . . .  34
     11.1.  Change from 18 to 19 . . . . . . . . . . . . . . . . . .  34
     11.2.  Change from 18 to 19 . . . . . . . . . . . . . . . . . .  34
     11.3.  Change from 17 to 18 . . . . . . . . . . . . . . . . . .  34
     11.4.  Change from 16 to 17 . . . . . . . . . . . . . . . . . .  35
     11.5.  Change from 15 to 16 . . . . . . . . . . . . . . . . . .  35
     11.6.  Change from 14 to 15 . . . . . . . . . . . . . . . . . .  35
     11.7.  Change from 13 to 14 . . . . . . . . . . . . . . . . . .  35
     11.8.  Change from 12 to 13 . . . . . . . . . . . . . . . . . .  35
     11.9.  Change from 11 to 12 . . . . . . . . . . . . . . . . . .  35
     11.10. Change from 10 to 11 . . . . . . . . . . . . . . . . . .  35
     11.11. Change from 09 to 10 . . . . . . . . . . . . . . . . . .  35
     11.12. Change from 08 to 09 . . . . . . . . . . . . . . . . . .  36
     11.13. Change from 07 to 08 . . . . . . . . . . . . . . . . . .  36
     11.14. Change from 06 to 07 . . . . . . . . . . . . . . . . . .  36
     11.15. Change from 05 to 06 . . . . . . . . . . . . . . . . . .  36
     11.16. Change from 04 to 05 . . . . . . . . . . . . . . . . . .  36
     11.17. Change from 03 to 04 . . . . . . . . . . . . . . . . . .  36
     11.18. Change from 02 to 03 . . . . . . . . . . . . . . . . . .  37
     11.19. Change from 01 to 02 . . . . . . . . . . . . . . . . . .  37
     11.20. Change from 00 to 01 . . . . . . . . . . . . . . . . . .  37
     11.21. Change from draft-brown-00 to draft-ietf-regext-fees-00   37
   12.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  37
     12.1.
     9.1.  Normative References . . . . . . . . . . . . . . . . . .  37
     12.2.
     9.2.  Informative References . . . . . . . . . . . . . . . . .  39
   Acknowledgements
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  39

1.  Introduction

   Historically, domain name registries have applied a simple fee
   structure for billable transactions, namely a basic unit price
   applied to domain <create>, <renew>, <transfer> <transfer>, and RGP Redemption Grace
   Period (RGP) [RFC3915] restore commands.  Given the relatively small
   number of EPP servers to which EPP clients have been required to
   connect, it has generally been the case that client operators have
   been able to obtain details of these fees out-of-band out of band by contacting
   the server operators.

   Given the expansion of the DNS namespace, namespace and the proliferation of
   novel business models, it is desirable to provide a method for EPP
   clients to query EPP servers for the fees and credits associated with
   various billable transactions and certain commands and specific
   objects.

   This document describes an extension mapping for version 1.0 of the
   Extensible Provisioning Protocol (EPP) [RFC5730].  This EPP mapping
   provides a mechanism by which EPP clients may query the fees and
   credits associated with various billable transactions, transactions and obtain
   their current account balance.

1.1.  Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   XML is case sensitive.  Unless stated otherwise, the XML
   specifications and examples provided in this document MUST be
   interpreted in the character case presented in order to develop a
   conforming implementation.

   "fee" is used as an abbreviation for "urn:ietf:params:xml:ns:epp:fee-
   1.0".  The XML namespace prefix "fee" is used, but implementations
   MUST NOT depend on it and instead employ a proper namespace-aware XML
   parser and serializer to interpret and output the XML documents.

   In the examples, "C:" represents lines sent by a protocol client client, and
   "S:" represents lines returned by a protocol server.  Indentation and
   white space in the examples are provided only to illustrate element
   relationships and are not a required feature of this protocol.

2.  Migrating to Newer Versions of This Extension

   Servers which that implement this extension SHOULD provide a way for
   clients to progressively update their implementations when a new
   version of the extension is deployed.

   Servers SHOULD (for a temporary migration period) provide support for
   older versions of the extension in parallel to the newest version, version and
   allow clients to select their preferred version via the
   <svcExtension> element of the <login> command.

   If a client requests multiple versions of the extension at login,
   then, when preparing responses to commands which that do not include
   extension elements, the server SHOULD only include extension elements
   in the namespace of the newest version of the extension requested by
   the client.

   When preparing responses to commands which that do include extension
   elements, the server SHOULD only include extension elements for the
   extension versions present in the command.

3.  Extension Elements

3.1.  Client Commands

   The <fee:command> element is used in the EPP <check> command to
   determine the fee that is applicable to the given command.

   The use "name" attribute of the <fee:command> keys off the use of the "name" attribute is used to define which
   transform fees the client is requesting information about.  Here is the list of  The
   possible values for the "name" attribute:

   o  "create" attribute are:

   *  "create", indicating a <create> command as defined in [RFC5730];
   o  "delete" [RFC5730].

   *  "delete", indicating a <delete> command as defined in [RFC5730];
   o  "renew" [RFC5730].

   *  "renew", indicating a <renew> command as defined in [RFC5730];
   o  "update" [RFC5730].

   *  "update", indicating a <update> command as defined in [RFC5730];
   o  "transfer" [RFC5730].

   *  "transfer", indicating a <transfer> command as defined in
      [RFC5730];
   o
      [RFC5730].

   *  If the server supports the Registry Grace Period Mapping registry grace period mapping [RFC3915],
      then the server MUST also support the "restore" value as defined
      in [RFC3915];
   o  "custom" [RFC3915].

   *  "custom", indicating a custom command that MUST set the
      "customName" attribute with a custom command name.  The possible
      set of custom command name values is up to dictated by the server
      policy.

   The <fee:command> element MAY have an OPTIONAL "phase" attribute
   specifying a launch phase as described in [RFC8334].  It may also
   contain an OPTIONAL "subphase" attribute identifying the custom or
   sub-phase
   subphase as described in [RFC8334].

3.2.  Currency Codes

   The <fee:currency> element is used to indicate which the currency in which
   fees are charged in.  This charged.  The value of this element MUST be a three-character three-
   character currency code from [ISO4217:2015]. [ISO4217_2015].

   Note that ISO 4217:2015 [ISO4217_2015] provides the special "XXX" code, which MAY
   be used if the server uses a non-currency based non-currency-based system for assessing
   fees, such as a system of credits.

   The use of <fee:currency> elements in client commands is OPTIONAL: if
   a <fee:currency> element is not present in a command, the server MUST
   determine the currency based on the server default currency or based on the
   client's account settings settings, which are agreed to by the client and
   server via an out-of-band channel.  However, the <fee:currency>
   element MUST be present in the responses.

   Servers SHOULD NOT perform a currency conversion if a client uses an
   incorrect currency code.  Servers SHOULD return a 2004 "Parameter
   value range" error range error" instead.

3.3.  Validity Periods

   When querying for fee information using the <check> command, the
   <fee:period> element is used to indicate the period measured in years
   or months, with the appropriate units specified using the "unit"
   attribute validity period, which
   is to be added to extend the registration period of objects by the
   <create>, <renew> <renew>, and <transfer> commands.  Validity periods are
   measured in years or months, with the appropriate units specified
   using the "unit" attribute.  Valid values for the "unit" attribute
   are "y" for years and "m" for months.  This element is derived from
   the <domain:period> element described in [RFC5731].

   The <fee:period> element is OPTIONAL in <check> commands, commands; if omitted,
   the server MUST determine the fee(s) using the server default period.
   The <fee:period> element MUST be present in <check> responses.

3.4.  Fees and Credits

   Servers which that implement this extension will include elements in
   responses which that provide information about the fees and/or credits
   associated with a given billable transaction.  A fee will result in
   subtracting from the Account Balance (described in Section 3.5) 3.5), and
   a credit will result in adding to the Account Balance (described in
   Section 3.5).

   The <fee:fee> and <fee:credit> elements are used to provide this
   information.  The presence of a <fee:fee> element in a response
   indicates a debit against the client's account balance; a
   <fee:credit> element indicates a credit.  A <fee:fee> element MUST
   have a zero or greater (non-negative) value.  A <fee:credit> element
   MUST have a negative value.

   A server MAY respond with multiple <fee:fee> and <fee:credit>
   elements in the same response.  In such cases, the net fee or credit
   applicable to the transaction is the arithmetic sum of the values of
   each of the <fee:fee> and/or <fee:credit> elements.  This amount
   applies to the total additional validity period applied to for the object (where
   applicable).

   The following attributes are defined for the <fee:fee> element.
   These are described in detail below:

   description:  an OPTIONAL attribute which that provides a human-readable
      description of the fee.  Servers should provide documentation on
      the possible values of this attribute, attribute and their meanings.  An
      OPTIONAL "lang" attribute MAY be present, per the language
      structure in [RFC5646], to identify the language of the returned
      text and has a default value of "en" (English).  If the
      "description" attribute is not present, the "lang" attribute can
      be ignored.

   refundable:  an OPTIONAL boolean attribute indicating whether the fee
      is refundable if the object is deleted.

   grace-period:  an OPTIONAL attribute which that provides the time period
      during which the fee is refundable.

   applied:  an OPTIONAL attribute indicating when the fee will be
      deducted from the client's account.

   The <fee:credit> element can take a "description" attribute as
   described above.  An OPTIONAL "lang" attribute MAY be present to
   identify the language of the returned text and has a default value of
   "en" (English).

3.4.1.  Refunds

   <fee:fee> elements MAY have an OPTIONAL "refundable" attribute which that
   takes a boolean value.  Fees may be refunded under certain
   circumstances, such as when a domain application is rejected (as
   described in [RFC8334]) or when an object is deleted during the
   relevant Grace Period grace period (see below). Section 3.4.2).

   If the "refundable" attribute is omitted, then clients SHOULD NOT
   make any assumption assumptions about the refundability of the fee.

3.4.2.  Grace Periods

   [RFC3915] describes a system of "grace periods", which are time
   periods following a billable transaction during which, if an object
   is deleted, the client receives a refund.

   The "grace-period" attribute MAY be used to indicate the relevant
   grace period for a fee.  If a server implements the Registry Grace
   Period registry grace
   period extension [RFC3915], it MUST specify the grace period for all
   relevant transactions.

   If the "grace-period" attribute is omitted, then clients SHOULD NOT
   make any assumption assumptions about the grace period of the fee.

3.4.3.  Correlation between Refundability and Grace Periods

   If a <fee:fee> element has a "grace-period" attribute attribute, then it MUST
   also be refundable refundable, and the "refundable" attribute MUST be true.  If
   the "refundable" attribute of a <fee:fee> element is false false, then it
   MUST NOT have a "grace-period" attribute.

3.4.4.  Applicability

   Fees may be applied immediately upon receipt of a command from a
   client,
   client or may only be applied once an out-of-band process (such as
   the processing of applications at the end of a launch phase) has
   taken place.

   The "applied" attribute of the <fee:fee> element allows servers to
   indicate whether a fee will be applied immediately, immediately or whether it will
   be applied at some point in the future.  This attribute takes two
   possible values: "immediate" or "delayed".

3.5.  Account Balance

   The <fee:balance> element is an OPTIONAL element which that MAY be included
   in server responses to transform commands.  If present, it can be
   used by the client to determine the remaining credit at the server.

   Whether or not the <fee:balance> is included in responses is a matter
   of server policy.  However, if a server chooses to offer support for
   this element, it MUST be included in responses to all "transform" or
   billable commands (e.g. (e.g., <create>, <renew>, <update>, <delete>,
   <transfer op="request">).

   The value of the <fee:balance> MAY be negative.  A negative balance
   indicates that the server has extended a line of credit to the client
   (see below). Section 3.6).

   If a server includes a <fee:balance> element in response to transform
   commands, the value of the element MUST reflect the client's account
   balance after any fees or credits associated with that command have
   been applied.  If the "applied" attribute of the <fee:fee> element is
   "delayed", then the <fee:balance> MUST reflect the client's account
   balance without any fees or credits associated with that command.

3.6.  Credit Limit

   As described above, if a server returns a response containing a
   <fee:balance> with a negative value, then the server has extended a
   line of credit to the client.  A server MAY also include in responses
   a <fee:creditLimit> element in responses that indicates the maximum credit
   available to a client.  A server MAY reject certain transactions if
   the absolute value of the <fee:balance> is equal to or exceeds the
   value of the <fee:creditLimit> element.

   Whether or not the <fee:creditLimit> is included in responses is a
   matter of server policy.  However, if a server chooses to offer
   support for this element, it MUST be included in responses to all
   "transform" commands (e.g. (e.g., <create>, <renew>, <update>, <delete>,
   <transfer op="request">).

3.7.  Classification of Objects

   Objects may be assigned to a particular class, category, or tier,
   each of which has a particular fee or set of fees associated with it.
   The <fee:class> element, which MAY appear in <check> and transform
   responses, is used to indicate the classification of an object.

   If a server makes use of this element, it should provide clients with
   a list of all the values that the element may take via an out-of-band
   channel.  Servers MUST NOT use values which that do not appear on this
   list.

   Servers that make use of this element MUST use a <fee:class> element
   with the value "standard" for all objects that are subject to the
   standard or default fee.

3.8.  Phase  "Phase" and Subphase "Subphase" Attributes

   The <fee:command> element has two attributes, phase "phase" and subphase, "subphase",
   that provide additional information related to a specific launch
   phase
   phase, as described in [RFC8334].  These attributes are used as
   filters that should refine the server processing.

   If the client <fee:command> contains a server supported server-supported combination
   of phase/subphase phase/subphase, the server MUST return the fee data (including the
   phase/subphase attribute(s)) for the specific combination.

   If the client <fee:command> contains no phase/subphase "phase"/"subphase" attributes
   and the server has only one active phase/subphase combination combination, the
   server MUST return the data (including the phase/subphase "phase"/"subphase"
   attribute(s)) of the currently active phase/subphase.

   If the client <fee:command> contains no phase/subphase attributes and
   the server has more than one active phase/subphase combination combination, the
   server MUST respond with a 2003 "Required parameter missing" error.

   If the client <fee:command> contains no phase/subphase attributes and
   the server is currently in a "quiet period" (e.g. (e.g., not accepting
   registrations or applications) applications), the server MUST return data
   consistent with the default general availability phase (e.g. (e.g., "open"
   or "claims") "claims"), including the appropriate phase/subphase attribute(s).

   If the client <fee:command> contains a phase attribute with no
   subphase and the server has only one active subphase (or no subphase)
   of this phase, the server MUST return the data (including the phase/
   subphase attribute(s)) of the provided phase and currently active
   subphase.

   If the client <fee:command> contains a phase attribute with no
   subphase and the server has more than one active subphase combination
   of this phase, the server MUST respond with a 2003 "Required
   parameter missing" error.

   If the client <fee:command> contains a subphase with no phase
   attribute
   attribute, the server MUST respond with a 2003 "Required parameter
   missing" error.

   If the client <fee:command> contains a phase attribute not defined in
   [RFC8334] or not supported by server the server, the server MUST respond
   with a 2004 "Parameter value range" error. range error".

   If the client <fee:command> contains a subphase attribute (or phase/
   subphase combination) not supported by server the server, the server MUST
   respond with a 2004 "Parameter value range" error. range error".

3.9.  Reason

   The <fee:reason> element is used to provide server specific server-specific text in
   an effort to better explain why a <check> command did not complete as
   the client expected.  An OPTIONAL "lang" attribute MAY be present to
   identify the language, per the language structure in [RFC5646], of
   the returned text and has a default value of "en" (English).

   The <fee:reason> element can be used within the server response
   <fee:command> element or within the <fee:cd> element.  See section
   Section 5.1.1 for details on the <fee:cd> "check data" element.

   If the server cannot calculate the relevant fees, fees because the object,
   command, currency, period, class class, or some combination is invalid per
   server policy, the server has two ways of handling the error
   processing of <fee:command> element(s):

   1.  Fast-fail -  Fast-fail: The server, upon error identification, MAY stop
       processing <fee:command> elements and return a <fee:cd> to the
       client a
       <fee:cd> containing the <fee:objID> and a <fee:reason> element
       detailing the reason for failure.

          S: <fee:cd avail="0">
          S:   <fee:objID>example.xyz</fee:objID>
          S:   <fee:reason>Only 1 year registration periods are
          S:   valid.</fee:reason>
          S: </fee:cd>

   2.  Partial-fail -  Partial-fail: The server, upon error identification, MAY continue
       processing <fee:command> elements and return a <fee:cd> to the
       client a <fee:cd> containing the successfully processed <fee:command>
       elements and failed <fee:command> elements.  All returned failed
       <fee:command> elements MUST have a <fee:reason> element detailing
       the reason for failure, and the server MAY additionally include a
       <fee:reason> element at the <fee:cd> level.

          S: <fee:cd avail="0">
          S:   <fee:objID>example.xyz</fee:objID>
          S:   <fee:command name="create">
          S:     <fee:period unit="y">2</fee:period>
          S:     <fee:reason>Only 1 year registration periods are
          S:     valid.</fee:reason>
          S:   </fee:command>
          S: </fee:cd>

   In either failure scenario scenario, the server MUST set the <fee:cd> avail "avail"
   attribute to false (0) (0), and the server MUST process all objects in
   the client request.

4.  Server Handling of Fee Information

   Depending on the server policy, a client MAY be required to include
   the extension elements described in this document for certain
   transform commands.  Servers must provide clear documentation to
   clients about the circumstances in which this extension must be used.

   The server MUST return avail="0" in its response to a <check> command
   for any object in the <check> command that does not include the
   <fee:check> extension for which where the server would likewise fail a domain <create>
   command when no <fee> extension is provided for that same object.

   If a server receives a <check> command from a client, which client that results in
   no possible fee combination, the server MUST set the "avail"
   attribute of the <fee:cd> element to false (0) and provide a
   <fee:reason>.

   If a server receives a <check> command from a client, which client that results in
   an ambiguous result (i.e. (i.e., multiple possible fee combinations) combinations), the
   server MUST reject the command with a 2003 "Required parameter
   missing" error.

   If a server receives a command from a client, which client that does not include
   the fee extension data elements required by the server for that
   command, then the server MUST respond with a 2003 "Required parameter
   missing" error.

   If the total fee provided by the client is less than the server's own
   calculation of the fee or the server determines the currency is
   inappropriate for that command, then the server MUST reject the
   command with a 2004 "Parameter value range" error. range error".

5.  EPP Command Mapping

   A detailed description of the EPP syntax and semantics can be found
   in [RFC5730].

5.1.  EPP Query Commands

   This extension does not add any elements to the EPP <poll> or <info>
   commands or responses.

5.1.1.  EPP <check> Command

   This extension defines a new command called the Fee Check Command
   that defines additional elements for the EPP <check> command to
   provide fee information along with the availability information of
   the EPP <check> command. information.

   The command MAY contain an <extension> element element, which MAY contain a
   <fee:check> element.  The <fee:check> element MAY contain one
   <fee:currency> element and MUST contain one or more <fee:command>
   elements.

   The <fee:command> element(s) MUST contain(s) contain a "name" attribute (see
   Section 3.1), an OPTIONAL "phase" attribute, and an OPTIONAL
   "subphase" attribute (see Section 3.8).  The <fee:command> element(s)
   MAY have the following child elements:

   o

   *  An OPTIONAL <fee:period> element (as described in Section 3.3).

   Example <check> command:

   C: <?xml version="1.0" encoding="utf-8" standalone="no"?>
   C: <epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   C:   <command>
   C:     <check>
   C:       <domain:check
   C:         xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
   C:         <domain:name>example.com</domain:name>
   C:         <domain:name>example.net</domain:name>
   C:         <domain:name>example.xyz</domain:name>
   C:       </domain:check>
   C:     </check>
   C:     <extension>
   C:       <fee:check xmlns:fee="urn:ietf:params:xml:ns:epp:fee-1.0">
   C:         <fee:currency>USD</fee:currency>
   C:         <fee:command name="create">
   C:           <fee:period unit="y">2</fee:period>
   C:         </fee:command>
   C:         <fee:command name="renew"/>
   C:         <fee:command name="transfer"/>
   C:         <fee:command name="restore"/>
   C:       </fee:check>
   C:     </extension>
   C:     <clTRID>ABC-12345</clTRID>
   C:   </command>
   C: </epp>

   When the server receives a <check> command that includes the
   extension elements described above, its response MUST contain an
   <extension> element, which MUST contain a child <fee:chkData>
   element.  The <fee:chkData> element MUST contain a <fee:currency>
   element and a <fee:cd> element for each object referenced in the
   client <check> command.

   Each <fee:cd> (check data) element MUST contain the following child
   elements:

   o

   *  A <fee:objID> element, which MUST match an element referenced in
      the client <check> command.
   o

   *  An OPTIONAL <fee:class> element (as described in Section 3.7).
   o

   *  A <fee:command> element matching each <fee:command> (unless the
      "avail" attribute of the <fee:cd> if is false) that appeared in the
      corresponding <fee:check> of the client command.  This element MAY
      have the OPTIONAL "standard" attribute, with a default value of
      "0" (or "false"), which indicates whether the fee matches is the standard
      or default fee
      of the "standard" classification (see section Section 3.7).  This element MAY have the
      OPTIONAL "phase" and "subphase" attributes, which will match the
      same attributes in the corresponding <fee:command> element of the
      client command if sent by the client.

   The <fee:cd> element also has an OPTIONAL "avail" attribute attribute, which is
   a boolean.  If the value of this attribute evaluates to false, this
   indicates that the server cannot calculate the relevant fees, fees because
   the object, command, currency, period, class class, or some combination is
   invalid per server policy.  If "avail" is false false, then the <fee:cd> or
   the <fee:command> element MUST contain a <fee:reason> element (as
   described in Section 3.9) 3.9), and the server MAY eliminate some or all
   of the <fee:command> element(s).

   The <fee:command> element(s) MAY have the following child elements:

   o

   *  An OPTIONAL <fee:period> element (as described in Section 3.3),
      which contains the same unit, if present, that appeared in the
      <fee:period> element of the command.  If the value of the parent
      <fee:command> element is "restore", this element MUST NOT be
      included, otherwise
      included; otherwise, it MUST be included.  If no <fee:period>
      appeared in the client command (and the command is not "restore") "restore"),
      then the server MUST return its default period value.
   o

   *  Zero or more <fee:fee> elements (as described in Section 3.4).
   o

   *  Zero or more <fee:credit> elements (as described in Section 3.4).
   o

   *  An OPTIONAL <fee:reason> element (as described in Section 3.9).

   If the "avail" attribute of the <fee:cd> element is true (1) and if
   no <fee:fee> elements are present in a <fee:command> element, this
   indicates that no fee will be assessed by the server for this
   command.

   If the "avail" attribute of the <fee:cd> element is true (1), then
   the <fee:command> element MUST NOT contain a <fee:reason> element.

   Example <check> response:

   S: <?xml version="1.0" encoding="utf-8" standalone="no"?>
   S: <epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:   <response>
   S:     <result code="1000">
   S:       <msg>Command completed successfully</msg>
   S:     </result>
   S:     <resData>
   S:       <domain:chkData
   S:         xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
   S:         <domain:cd>
   S:           <domain:name avail="1">example.com</domain:name>
   S:         </domain:cd>
   S:         <domain:cd>
   S:           <domain:name avail="1">example.net</domain:name>
   S:         </domain:cd>
   S:         <domain:cd>
   S:           <domain:name avail="1">example.xyz</domain:name>
   S:         </domain:cd>
   S:       </domain:chkData>
   S:     </resData>
   S:     <extension>
   S:       <fee:chkData
   S:           xmlns:fee="urn:ietf:params:xml:ns:epp:fee-1.0">
   S:         <fee:currency>USD</fee:currency>
   S:         <fee:cd avail="1">
   S:           <fee:objID>example.com</fee:objID>
   S:           <fee:class>Premium</fee:class>
   S:           <fee:command name="create">
   S:             <fee:period unit="y">2</fee:period>
   S:             <fee:fee
   S:               description="Registration Fee"
   S:               refundable="1"
   S:               grace-period="P5D">10.00</fee:fee>
   S:           </fee:command>
   S:           <fee:command name="renew">
   S:             <fee:period unit="y">1</fee:period>
   S:             <fee:fee
   S:               description="Renewal Fee"
   S:               refundable="1"
   S:               grace-period="P5D">10.00</fee:fee>
   S:           </fee:command>
   S:           <fee:command name="transfer">
   S:             <fee:period unit="y">1</fee:period>
   S:             <fee:fee
   S:               description="Transfer Fee"
   S:               refundable="1"
   S:               grace-period="P5D">10.00</fee:fee>
   S:           </fee:command>
   S:           <fee:command name="restore">
   S:             <fee:fee
   S:               description="Redemption Fee">15.00</fee:fee>
   S:           </fee:command>
   S:         </fee:cd>
   S:         <fee:cd avail="1">
   S:           <fee:objID>example.net</fee:objID>
   S:           <fee:class>standard</fee:class>
   S:           <fee:command name="create" standard="1">
   S:             <fee:period unit="y">2</fee:period>
   S:             <fee:fee
   S:               description="Registration Fee"
   S:               refundable="1"
   S:               grace-period="P5D">5.00</fee:fee>
   S:           </fee:command>
   S:           <fee:command name="renew" standard="1">
   S:             <fee:period unit="y">1</fee:period>
   S:             <fee:fee
   S:               description="Renewal Fee"
   S:               refundable="1"
   S:               grace-period="P5D">5.00</fee:fee>
   S:           </fee:command>
   S:           <fee:command name="transfer" standard="1">
   S:             <fee:period unit="y">1</fee:period>
   S:             <fee:fee
   S:               description="Transfer Fee"
   S:               refundable="1"
   S:               grace-period="P5D">5.00</fee:fee>
   S:           </fee:command>
   S:           <fee:command name="restore" standard="1">
   S:             <fee:fee
   S:               description="Redemption Fee">5.00</fee:fee>
   S:           </fee:command>
   S:         </fee:cd>
   S:         <fee:cd avail="0">
   S:           <fee:objID>example.xyz</fee:objID>
   S:           <fee:command name="create">
   S:             <fee:period unit="y">2</fee:period>
   S:             <fee:reason>Only 1 year registration periods are
   S:               valid.</fee:reason>
   S:           </fee:command>
   S:         </fee:cd>
   S:       </fee:chkData>
   S:     </extension>
   S:     <trID>
   S:       <clTRID>ABC-12345</clTRID>
   S:       <svTRID>54322-XYZ</svTRID>
   S:     </trID>
   S:   </response>
   S: </epp>

5.1.2.  EPP Transfer Query Command

   This extension does not add any elements to the EPP <transfer> query
   command, but it does include elements in the response, response when the
   extension is included in the <login> command service extensions.

   When the <transfer> query command has been processed successfully, if
   the client has included the extension in the <login> command service
   <svcExtension> element, and if the client is authorized by the server
   to view information about the transfer, then the server MAY include
   in the <extension> section of the EPP response a <fee:trnData>
   element, which contains the following child elements:

   o

   *  A <fee:currency> element (as described in Section 3.2).
   o

   *  A <fee:period> element (as described in Section 3.3).
   o

   *  Zero or more <fee:fee> elements (as described in Section 3.4)
      containing the fees that will be charged to the gaining client.
   o

   *  Zero or more <fee:credit> elements (as described in Section 3.4)
      containing the credits that will be refunded to the losing client.

   Servers SHOULD omit <fee:credit> when returning a response to the
   gaining client, client and omit <fee:fee> elements when returning a response
   to the losing client.

   If no <fee:trnData> element is included in the response, then no fee
   will be assessed by the server for the transfer.

   Example <transfer> query response:

   S: <?xml version="1.0" encoding="utf-8" standalone="no"?>
   S: <epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:   <response>
   S:     <result code="1001">
   S:       <msg>Command completed successfully; action pending</msg>
   S:     </result>
   S:     <resData>
   S:       <domain:trnData
   S:         xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
   S:         <domain:name>example.com</domain:name>
   S:         <domain:trStatus>pending</domain:trStatus>
   S:         <domain:reID>ClientX</domain:reID>
   S:         <domain:reDate>2019-06-08T22:00:00.0Z</domain:reDate>
   S:         <domain:acID>ClientY</domain:acID>
   S:         <domain:acDate>2019-06-13T22:00:00.0Z</domain:acDate>
   S:         <domain:exDate>2021-09-08T22:00:00.0Z</domain:exDate>
   S:       </domain:trnData>
   S:     </resData>
   S:     <extension>
   S:       <fee:trnData xmlns:fee="urn:ietf:params:xml:ns:epp:fee-1.0">
   S:         <fee:currency>USD</fee:currency>
   S:         <fee:period unit="y">1</fee:period>
   S:         <fee:fee>5.00</fee:fee>
   S:       </fee:trnData>
   S:     </extension>
   S:     <trID>
   S:       <clTRID>ABC-12345</clTRID>
   S:       <svTRID>54322-XYZ</svTRID>
   S:     </trID>
   S:   </response>
   S: </epp>

5.2.  EPP Transform Commands

5.2.1.  EPP <create> Command

   This extension adds elements to both the EPP <create> command and
   response,
   response when the extension is included in the <login> command
   service extensions.

   When submitting a <create> command to the server, the client MAY
   include in the <extension> element a <fee:create> element element, which
   includes the following child elements:

   o

   *  An OPTIONAL <fee:currency> element (as described in Section 3.2);
   o 3.2).

   *  One or more <fee:fee> elements (as described in Section 3.4).

   When the <create> command has been processed successfully, and the client
   included the extension in the <login> command service extensions, and
   a fee was assessed by the server for the transaction, the server MUST
   include in the <extension> section of the EPP response a
   <fee:creData> element, which contains the following child elements:

   o

   *  A <fee:currency> element (as described in Section 3.2);
   o 3.2).

   *  Zero or more <fee:fee> elements (as described in Section 3.4);
   o 3.4).

   *  Zero or more <fee:credit> elements (as described in Section 3.4);
   o 3.4).

   *  An OPTIONAL <fee:balance> element (as described in Section 3.5);
   o 3.5).

   *  An OPTIONAL <fee:creditLimit> element (as described in
      Section 3.6).

   Example <create> command:

   C: <?xml version="1.0" encoding="utf-8" standalone="no"?>
   C: <epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   C:   <command>
   C:     <create>
   C:       <domain:create
   C:         xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
   C:         <domain:name>example.com</domain:name>
   C:         <domain:period unit="y">2</domain:period>
   C:         <domain:ns>
   C:           <domain:hostObj>ns1.example.net</domain:hostObj>
   C:           <domain:hostObj>ns2.example.net</domain:hostObj>
   C:         </domain:ns>
   C:         <domain:registrant>jd1234</domain:registrant>
   C:         <domain:contact type="admin">sh8013</domain:contact>
   C:         <domain:contact type="tech">sh8013</domain:contact>
   C:         <domain:authInfo>
   C:           <domain:pw>2fooBAR</domain:pw>
   C:         </domain:authInfo>
   C:       </domain:create>
   C:     </create>
   C:     <extension>
   C:       <fee:create xmlns:fee="urn:ietf:params:xml:ns:epp:fee-1.0">
   C:         <fee:currency>USD</fee:currency>
   C:         <fee:fee>5.00</fee:fee>
   C:       </fee:create>
   C:     </extension>
   C:     <clTRID>ABC-12345</clTRID>
   C:   </command>
   C: </epp>

   Example <create> response:

   S: <?xml version="1.0" encoding="utf-8" standalone="no"?>
   S: <epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:   <response>
   S:     <result code="1000">
   S:       <msg>Command completed successfully</msg>
   S:     </result>
   S:     <resData>
   S:       <domain:creData
   S:         xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
   S:         <domain:name>example.com</domain:name>
   S:         <domain:crDate>2019-04-03T22:00:00.0Z</domain:crDate>
   S:         <domain:exDate>2021-04-03T22:00:00.0Z</domain:exDate>
   S:       </domain:creData>
   S:     </resData>
   S:     <extension>
   S:       <fee:creData xmlns:fee="urn:ietf:params:xml:ns:epp:fee-1.0">
   S:         <fee:currency>USD</fee:currency>
   S:         <fee:fee
   S:           description="Registration Fee"
   S:           lang="en"
   S:           refundable="1"
   S:           grace-period="P5D">5.00</fee:fee>
   S:         <fee:balance>-5.00</fee:balance>
   S:         <fee:creditLimit>1000.00</fee:creditLimit>
   S:       </fee:creData>
   S:     </extension>
   S:     <trID>
   S:       <clTRID>ABC-12345</clTRID>
   S:       <svTRID>54321-XYZ</svTRID>
   S:     </trID>
   S:   </response>
   S: </epp>

5.2.2.  EPP <delete> Command

   This extension does not add any elements to the EPP <delete> command,
   but it does include elements in the response, response when the extension is
   included in the <login> command service extensions.

   When the <delete> command has been processed successfully, successfully and the
   client included the extension in the <login> command service
   extensions, the server MAY include in the <extension> section of the
   EPP response a <fee:delData> element, which contains the following
   child elements:

   o

   *  A <fee:currency> element (as described in Section 3.2);
   o 3.2).

   *  Zero or more <fee:fee> elements (as described in Section 3.4);
   o 3.4).

   *  Zero or more <fee:credit> elements (as described in Section 3.4);
   o 3.4).

   *  An OPTIONAL <fee:balance> element (as described in Section 3.5);
   o 3.5).

   *  An OPTIONAL <fee:creditLimit> element (as described in
      Section 3.6).

   Example <delete> response:

   S: <?xml version="1.0" encoding="utf-8" standalone="no"?>
   S: <epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:   <response>
   S:     <result code="1000">
   S:       <msg>Command completed successfully</msg>
   S:     </result>
   S:     <extension>
   S:       <fee:delData
   S:         xmlns:fee="urn:ietf:params:xml:ns:epp:fee-1.0">
   S:         <fee:currency>USD</fee:currency>
   S:         <fee:credit
   S:           description="AGP Credit"
   S:           lang="en">-5.00</fee:credit>
   S:         <fee:balance>1005.00</fee:balance>
   S:       </fee:delData>
   S:     </extension>
   S:     <trID>
   S:       <clTRID>ABC-12345</clTRID>
   S:       <svTRID>54321-XYZ</svTRID>
   S:     </trID>
   S:   </response>
   S: </epp>

5.2.3.  EPP <renew> Command

   This extension adds elements to both the EPP <renew> command and
   response,
   response when the extension is included in the <login> command
   service extensions.

   When submitting a <renew> command to the server, the client MAY
   include in the <extension> element a <fee:renew> element element, which
   includes the following child elements:

   o

   *  An OPTIONAL <fee:currency> element (as described in Section 3.2);
   o 3.2).

   *  One or more <fee:fee> elements (as described in Section 3.4).

   When the <renew> command has been processed successfully, successfully and the
   client included the extension in the <login> command service
   extensions, the server MAY include in the <extension> section of the
   EPP response a <fee:renData> element, which contains the following
   child elements:

   o

   *  A <fee:currency> element (as described in Section 3.2);
   o 3.2).

   *  Zero or more <fee:fee> elements (as described in Section 3.4);
   o 3.4).

   *  Zero or more <fee:credit> elements (as described in Section 3.4);
   o 3.4).

   *  An OPTIONAL <fee:balance> element (as described in Section 3.5);
   o 3.5).

   *  An OPTIONAL <fee:creditLimit> element (as described in
      Section 3.6).

   Example <renew> command:

   C: <?xml version="1.0" encoding="utf-8" standalone="no"?>
   C: <epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   C:   <command>
   C:     <renew>
   C:       <domain:renew
   C:         xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
   C:         <domain:name>example.com</domain:name>
   C:         <domain:curExpDate>2019-04-03</domain:curExpDate>
   C:         <domain:period unit="y">5</domain:period>
   C:       </domain:renew>
   C:     </renew>
   C:     <extension>
   C:       <fee:renew xmlns:fee="urn:ietf:params:xml:ns:epp:fee-1.0">
   C:         <fee:currency>USD</fee:currency>
   C:         <fee:fee>5.00</fee:fee>
   C:       </fee:renew>
   C:     </extension>
   C:     <clTRID>ABC-12345</clTRID>
   C:   </command>
   C: </epp>

   Example <renew> response:

   S: <?xml version="1.0" encoding="utf-8" standalone="no"?>
   S: <epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:   <response>
   S:     <result code="1000">
   S:       <msg>Command completed successfully</msg>
   S:     </result>
   S:     <resData>
   S:       <domain:renData
   S:         xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
   S:         <domain:name>example.com</domain:name>
   S:         <domain:exDate>2024-04-03T22:00:00.0Z</domain:exDate>
   S:       </domain:renData>
   S:     </resData>
   S:     <extension>
   S:       <fee:renData xmlns:fee="urn:ietf:params:xml:ns:epp:fee-1.0">
   S:         <fee:currency>USD</fee:currency>
   S:         <fee:fee
   S:           refundable="1"
   S:           grace-period="P5D">5.00</fee:fee>
   S:         <fee:balance>1000.00</fee:balance>
   S:       </fee:renData>
   S:     </extension>
   S:     <trID>
   S:       <clTRID>ABC-12345</clTRID>
   S:       <svTRID>54322-XYZ</svTRID>
   S:     </trID>
   S:   </response>
   S: </epp>

5.2.4.  EPP <transfer> Command

   This extension adds elements to both the EPP <transfer> command and
   response,
   response when the value of the "op" attribute of the <transfer>
   command element is "request", "request" and the extension is included in the
   <login> command service extensions.

   When submitting a <transfer> command to the server, the client MAY
   include in the <extension> element a <fee:transfer> element element, which
   includes the following child elements:

   o

   *  An OPTIONAL <fee:currency> element (as described in Section 3.2);
   o 3.2).

   *  One or more <fee:fee> elements (as described in Section 3.4).

   When the <transfer> command has been processed successfully, successfully and the
   client included the extension in the <login> command service
   extensions, the server MAY include in the <extension> section of the
   EPP response a <fee:trnData> element, which contains the following
   child elements:

   o

   *  A <fee:currency> element (as described in Section 3.2);
   o 3.2).

   *  Zero or more <fee:fee> elements (as described in Section 3.4);
   o 3.4).

   *  Zero or more <fee:credit> elements (as described in Section 3.4);
   o 3.4).

   *  An OPTIONAL <fee:balance> element (as described in Section 3.5);
   o 3.5).

   *  An OPTIONAL <fee:creditLimit> element (as described in
      Section 3.6).

   Example <transfer> command:

   C: <?xml version="1.0" encoding="utf-8" standalone="no"?>
   C: <epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   C:   <command>
   C:     <transfer op="request">
   C:       <domain:transfer
   C:         xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
   C:         <domain:name>example.com</domain:name>
   C:         <domain:period unit="y">1</domain:period>
   C:         <domain:authInfo>
   C:           <domain:pw roid="JD1234-REP">2fooBAR</domain:pw>
   C:         </domain:authInfo>
   C:       </domain:transfer>
   C:     </transfer>
   C:     <extension>
   C:      <fee:transfer xmlns:fee="urn:ietf:params:xml:ns:epp:fee-1.0">
   C:        <fee:currency>USD</fee:currency>
   C:        <fee:fee>5.00</fee:fee>
   C:      </fee:transfer>
   C:     </extension>
   C:     <clTRID>ABC-12345</clTRID>
   C:   </command>
   C: </epp>

   Example <transfer> response:

   S: <?xml version="1.0" encoding="utf-8" standalone="no"?>
   S: <epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:   <response>
   S:     <result code="1001">
   S:       <msg>Command completed successfully; action pending</msg>
   S:     </result>
   S:     <resData>
   S:       <domain:trnData
   S:         xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
   S:         <domain:name>example.com</domain:name>
   S:         <domain:trStatus>pending</domain:trStatus>
   S:         <domain:reID>ClientX</domain:reID>
   S:         <domain:reDate>2019-06-08T22:00:00.0Z</domain:reDate>
   S:         <domain:acID>ClientY</domain:acID>
   S:         <domain:acDate>2019-06-13T22:00:00.0Z</domain:acDate>
   S:         <domain:exDate>2021-09-08T22:00:00.0Z</domain:exDate>
   S:       </domain:trnData>
   S:     </resData>
   S:     <extension>
   S:       <fee:trnData xmlns:fee="urn:ietf:params:xml:ns:epp:fee-1.0">
   S:         <fee:currency>USD</fee:currency>
   S:         <fee:fee
   S:           refundable="1"
   S:           grace-period="P5D">5.00</fee:fee>
   S:       </fee:trnData>
   S:     </extension>
   S:     <trID>
   S:       <clTRID>ABC-12345</clTRID>
   S:       <svTRID>54322-XYZ</svTRID>
   S:     </trID>
   S:   </response>
   S: </epp>

5.2.5.  EPP <update> Command

   This extension adds elements to both the EPP <update> command and
   response,
   response when the extension is included in the <login> command
   service extensions.

   When submitting a an <update> command to the server, the client MAY
   include in the <extension> element a <fee:update> element element, which
   includes the following child elements:

   o

   *  An OPTIONAL <fee:currency> element (as described in Section 3.2);
   o 3.2).

   *  One or more <fee:fee> elements (as described in Section 3.4).

   When the <update> command has been processed successfully, successfully and the
   client included the extension in the <login> command service
   extensions, the server MAY include in the <extension> section of the
   EPP response a <fee:updData> element, which contains the following
   child elements:

   o

   *  A <fee:currency> element (as described in Section 3.2);
   o 3.2).

   *  Zero or more <fee:fee> elements (as described in Section 3.4);
   o 3.4).

   *  Zero or more <fee:credit> elements (as described in Section 3.4);
   o 3.4).

   *  An OPTIONAL <fee:balance> element (as described in Section 3.5);
   o 3.5).

   *  An OPTIONAL <fee:creditLimit> element (as described in
      Section 3.6).

   Example <update> command:

   C: <?xml version="1.0" encoding="utf-8" standalone="no"?>
   C: <epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   C:   <command>
   C:     <update>
   C:       <domain:update
   C:         xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
   C:         <domain:name>example.com</domain:name>
   C:         <domain:chg>
   C:           <domain:registrant>sh8013</domain:registrant>
   C:         </domain:chg>
   C:       </domain:update>
   C:     </update>
   C:     <extension>
   C:       <fee:update xmlns:fee="urn:ietf:params:xml:ns:epp:fee-1.0">
   C:         <fee:currency>USD</fee:currency>
   C:         <fee:fee>5.00</fee:fee>
   C:       </fee:update>
   C:     </extension>
   C:     <clTRID>ABC-12345</clTRID>
   C:   </command>
   C: </epp>

   Example <update> response:

   S: <?xml version="1.0" encoding="utf-8" standalone="no"?>
   S: <epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:   <response>
   S:     <result code="1000">
   S:       <msg>Command completed successfully</msg>
   S:     </result>
   S:     <extension>
   S:       <fee:updData xmlns:fee="urn:ietf:params:xml:ns:epp:fee-1.0">
   S:         <fee:currency>USD</fee:currency>
   S:         <fee:fee>5.00</fee:fee>
   S:       </fee:updData>
   S:     </extension>
   S:     <trID>
   S:       <clTRID>ABC-12345</clTRID>
   S:       <svTRID>54321-XYZ</svTRID>
   S:     </trID>
   S:   </response>
   S: </epp>

6.  Formal Syntax

   One schema is presented here that is -- the EPP Fee Extension schema.

   The formal syntax presented here is a complete schema representation
   of the object mapping suitable for automated validation of EPP XML
   instances.  The BEGIN and END tags are not part of the schema; they
   are used to note the beginning and ending of the schema for URI
   registration purposes.

6.1.  Fee Extension Schema

   The formal syntax presented here is a complete schema representation
   [W3C.REC-xmlschema-1-20041028] of the object mapping suitable for
   automated validation of EPP XML instances.  The BEGIN <CODE BEGINS> and END
   <CODE ENDS> tags are not part of the schema; they are used to note
   the beginning and ending end of the schema for URI registration purposes.

  BEGIN

   <CODE BEGINS>
   <?xml version="1.0" encoding="utf-8"?>
   <schema xmlns="http://www.w3.org/2001/XMLSchema"
     xmlns:fee="urn:ietf:params:xml:ns:epp:fee-1.0"
     xmlns:eppcom="urn:ietf:params:xml:ns:eppcom-1.0"
     xmlns:domain="urn:ietf:params:xml:ns:domain-1.0"
     targetNamespace="urn:ietf:params:xml:ns:epp:fee-1.0"
     elementFormDefault="qualified">

     <import namespace="urn:ietf:params:xml:ns:eppcom-1.0" />
     <import namespace="urn:ietf:params:xml:ns:domain-1.0" />

     <annotation>
       <documentation>
         Extensible Provisioning Protocol v1.0 Fee Extension
       </documentation>
     </annotation>

     <!-- Child elements found in EPP commands and responses -->
     <element name="check" type="fee:checkType" />
     <element name="chkData" type="fee:chkDataType" />
     <element name="create" type="fee:transformCommandType" />
     <element name="creData" type="fee:transformResultType" />
     <element name="renew" type="fee:transformCommandType" />
     <element name="renData" type="fee:transformResultType" />
     <element name="transfer" type="fee:transformCommandType" />
     <element name="trnData" type="fee:transformResultType" />
     <element name="update" type="fee:transformCommandType" />
     <element name="updData" type="fee:transformResultType" />
     <element name="delData" type="fee:transformResultType" />

     <!-- client <check> command -->
     <complexType name="checkType">
       <sequence>
         <element name="currency" type="fee:currencyType"
           minOccurs="0" />
         <element name="command" type="fee:commandType"
           minOccurs="1" maxOccurs="unbounded" />
       </sequence>
     </complexType>

     <complexType name="objectIdentifierType">
       <simpleContent>
         <extension base="eppcom:labelType">
           <attribute name="element"
           type="NMTOKEN" default="name" />
         </extension>
       </simpleContent>
     </complexType>

     <!-- server <check> result -->
     <complexType name="chkDataType">
       <sequence>
         <element name="currency" type="fee:currencyType" />
         <element name="cd" type="fee:objectCDType"
           maxOccurs="unbounded" />
       </sequence>
     </complexType>

     <complexType name="objectCDType">
       <sequence>
         <element name="objID" type="fee:objectIdentifierType" />
         <element name="class" type="token" minOccurs="0" />
         <element name="command" type="fee:commandDataType"
           minOccurs="0" maxOccurs="unbounded" />
         <element name="reason" type="fee:reasonType" minOccurs="0" />
       </sequence>
       <attribute name="avail" type="boolean" default="1" />
     </complexType>

     <!-- general transform (create, renew, update, transfer) command --> command-->
     <complexType name="transformCommandType">
       <sequence>
         <element name="currency" type="fee:currencyType"
           minOccurs="0" />
         <element name="fee" type="fee:feeType"
           maxOccurs="unbounded" />
         <element name="credit" type="fee:creditType"
           minOccurs="0" maxOccurs="unbounded" />
       </sequence>
     </complexType>

     <!-- general transform (create, renew, update) result -->
     <complexType name="transformResultType">
       <sequence>
         <element name="currency" type="fee:currencyType"
           minOccurs="0" />
         <element name="period" type="domain:periodType"
           minOccurs="0" />
         <element name="fee" type="fee:feeType"
           minOccurs="0" maxOccurs="unbounded" />
         <element name="credit" type="fee:creditType"
           minOccurs="0" maxOccurs="unbounded" />
         <element name="balance" type="fee:balanceType"
           minOccurs="0" />
         <element name="creditLimit" type="fee:creditLimitType"
           minOccurs="0" />
       </sequence>
     </complexType>

     <!-- common types -->
     <simpleType name="currencyType">
       <restriction base="string">
         <pattern value="[A-Z]{3}" />
       </restriction>
     </simpleType>

     <complexType name="commandType">
       <sequence>
         <element name="period" type="domain:periodType"
           minOccurs="0" maxOccurs="1" />
       </sequence>
       <attribute name="name" type="fee:commandEnum" use="required"/>
       <attribute name="customName" type="token"/>
       <attribute name="phase" type="token" />
       <attribute name="subphase" type="token" />
     </complexType>

     <complexType name="commandDataType">
       <complexContent>
         <extension base="fee:commandType">
           <sequence>
             <element name="fee" type="fee:feeType"
               minOccurs="0" maxOccurs="unbounded" />
             <element name="credit" type="fee:creditType"
               minOccurs="0" maxOccurs="unbounded" />
             <element name="reason" type="fee:reasonType"
               minOccurs="0" />
           </sequence>
           <attribute name="standard" type="boolean" default="0" />
         </extension>
       </complexContent>
     </complexType>

     <complexType name="reasonType">
       <simpleContent>
         <extension base="token">
           <attribute name="lang" type="language" default="en"/>
         </extension>
       </simpleContent>
     </complexType>

     <simpleType name="commandEnum">
       <restriction base="token">
         <enumeration value="create"/>
         <enumeration value="delete"/>
         <enumeration value="renew"/>
         <enumeration value="update"/>
         <enumeration value="transfer"/>
         <enumeration value="restore"/>
         <enumeration value="custom"/>
       </restriction>
     </simpleType>

     <simpleType name="nonNegativeDecimal">
       <restriction base="decimal">
         <minInclusive value="0" />
       </restriction>
     </simpleType>

     <simpleType name="negativeDecimal">
       <restriction base="decimal">
         <maxInclusive value="0" />
       </restriction>
     </simpleType>

     <complexType name="feeType">
       <simpleContent>
         <extension base="fee:nonNegativeDecimal">
           <attribute name="description"/>
           <attribute name="lang" type="language" default="en"/>
           <attribute name="refundable" type="boolean" />
           <attribute name="grace-period" type="duration" />
           <attribute name="applied">
             <simpleType>
               <restriction base="token">
                 <enumeration value="immediate" />
                 <enumeration value="delayed" />
               </restriction>
             </simpleType>
           </attribute>
         </extension>
       </simpleContent>
     </complexType>

     <complexType name="creditType">
       <simpleContent>
         <extension base="fee:negativeDecimal">
           <attribute name="description"/>
           <attribute name="lang" type="language" default="en"/>
         </extension>
       </simpleContent>
     </complexType>

     <simpleType name="balanceType">
       <restriction base="decimal" />
     </simpleType>

     <simpleType name="creditLimitType">
       <restriction base="decimal" />
     </simpleType>

   </schema>
  END
   <CODE ENDS>

7.  Security Considerations

   The mapping extensions described in this document do not provide any
   security services beyond those described by the EPP [RFC5730], the
   EPP domain name mapping [RFC5731], and the protocol layers used by
   the EPP.  The security considerations described in these other
   specifications apply to this specification as well.  This extension
   passes financial information using the EPP protocol, so
   confidentiality and integrity protection must be provided by the
   transport mechanism.  All transports compliant with [RFC5730] provide
   the needed level of confidentiality and integrity protections.  The
   server will only provide information, including financial
   information, that is relevant to the authenticated client.

8.  IANA Considerations

8.1.  XML Namespace

   This document uses URNs to describe XML namespaces and XML schemas
   conforming to a registry mechanism described in [RFC3688].

   Registration request for the fee namespace:

   URI: urn:ietf:params:xml:ns:epp:fee-1.0

   Registrant Contact: IESG

   XML: None.  Namespace URIs do not represent an XML specification.

   Registration request for the fee schema:

   URI: urn:ietf:params:xml:schema:epp:fee-1.0

   Registrant Contact: IESG

   XML: See the "Formal Syntax" section Section 6 of this document.

8.2.  EPP Extension Registry

   The EPP extension described in this document should be has been registered by
   the
   IANA in the EPP Extension Registry "Extensions for the Extensible Provisioning Protocol
   (EPP)" registry described in [RFC7451].  The details of the
   registration are as follows:

   Name of Extension: Registry Fee Extension for the Extensible
   Provisioning Protocol (EPP)

   Document status: Standards Track

   Reference: (insert reference to RFC version of this document) 8748

   Registrant Name and Email Address: IESG, IESG <iesg@ietf.org>

   TLDs: Any

   IPR Disclosure: None

   Status: Active

   Notes: None

9.  Implementation Status

   Note to RFC Editor: Please remove this section and the reference to
   [RFC7942] before publication.

   This section records the status of known implementations of the
   protocol defined by this specification at  References

9.1.  Normative References

   [ISO4217_2015]
              ISO, "Codes for the time of posting of this
   Internet-Draft, and is based on a proposal described in [RFC7942].
   The description representation of implementations in this section is intended to
   assist the IETF in its decision processes currencies",
              ISO 4217:2015, August 2015,
              <https://www.iso.org/standard/64758.html>.

   [RFC2119]  Bradner, S., "Key words for use in progressing drafts to
   RFCs.  Please note that the listing of any individual implementation
   here does not imply endorsement by the IETF.  Furthermore, no effort
   has been spent RFCs to verify the information presented here that was
   supplied by Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC3688]  Mealling, M., "The IETF contributors.  This is not intended as, and must not
   be construed to be, a catalog of available implementations or their
   features.  Readers are advised to note that other implementations may
   exist.

   According to [RFC7942], "this will allow reviewers and working groups
   to assign due consideration to documents that have the benefit of
   running code, which may serve as evidence of valuable experimentation
   and feedback that have made the implemented protocols more mature.
   It is up to the individual working groups to use this information as
   they see fit".

9.1.  RegistryEngine EPP Service

   Organization: CentralNic

   Name: RegistryEngine EPP Service

   Description: Generic high-volume EPP service XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC3915]  Hollenbeck, S., "Domain Registry Grace Period Mapping for gTLDs, ccTLDs and
   SLDs
   Level of maturity: Deployed in CentralNic's production environment as
   well as two other gTLD registry systems, and two ccTLD registry
   systems.

   Coverage: All aspects of the protocol are implemented.

   Licensing: Proprietary In-House software

   Contact: epp@centralnic.com

   URL: https://www.centralnic.com

10.  Acknowledgements

   The authors wish to thank
              the following persons Extensible Provisioning Protocol (EPP)", RFC 3915,
              DOI 10.17487/RFC3915, September 2004,
              <https://www.rfc-editor.org/info/rfc3915>.

   [RFC5646]  Phillips, A., Ed. and M. Davis, Ed., "Tags for their feedback
   and suggestions:

   o  James Gould of Verisign Inc
   o  Luis Munoz of ISC
   o  Michael Young of Architelos
   o  Ben Levac and Jeff Eckhaus of Demand Media
   o  Seth Goldman of Google
   o  Klaus Malorny and Michael Bauland of Knipp
   o  Jody Kolker, Joe Snitker and Kevin Allendorf of Go Daddy
   o  Michael Holloway of Com Laude
   o  Santosh Kalsangrah of Impetus Infotech
   o  Alex Mayrhofer of Nic.at
   o  Thomas Corte of Knipp Medien und Kommunikation GmbH

11.  Change History

11.1.  Change from 18 to 19

   Added normative reference for XML Schema.

11.2.  Change from 18 to 19

   Updated per IESG review, all updates (except for one schema change)
   were just textual for clarity and correctness.  The schema change was
   to require the name attribute of the commandType element.

11.3.  Change from 17 to 18

   Corrected erroneous edit left in place in previous revision (17),
   reverted text back to original text (revision 16) in section 3.4.

11.4.  Change from 16 to 17

   Updated per AD review, all updates were just textual for clarity and
   correctness.

11.5.  Change from 15 to 16

   Updated per AD review and list comments: several grammar corrections;
   clarification text added to section 3.4.3 and 3.5; and a schema
   update for consistency by providing a "lang" attribute to the
   <fee:fee> and <fee:credit> "description" attribute detailed in
   section 3.4.

11.6.  Change from 14 to 15

   Updated schema, moving the "standard" attribute of the
   "commandDataType" inside the <extension> block.

11.7.  Change from 13 to 14

   Moved RFC 7451 reference from Normative to Informative section.

11.8.  Change from 12 to 13

   Updated XML namespace and schema registration to be "epp" scoped -
   global replace of XML namespace from urn:ietf:params:xml:ns:fee-1.0
   to urn:ietf:params:xml:ns:epp:fee-1.0 and the XML schema registration
   from urn:ietf:params:xml:schema:fee-1.0 to
   urn:ietf:params:xml:schema:epp:fee-1.0.

11.9.  Change from 11 to 12

   Updated references to current version of documents and moved the
   "standard" attribute from the check command (commandType) to the
   check response (commandDataType).

11.10.  Change from 10 to 11

   Updated document per Working Group Last Call comments.  Made minor
   textual changes throughout for enhanced clarity per WGLC comments.

11.11.  Change from 09 to 10

   Updated document per Working Group Last Call comments.  Updated
   schema to version 1.0 in anticipation of standardization, no changes
   were made to the latest, 0.25, schema.  Made minor textual changes
   throughout for enhanced clarity per WGLC comments.

11.12.  Change from 08 to 09

   Updated scheme to version 0.25 to allow tighter checking on
   <fee:command> by splitting the client and server definitions, moved
   the class element from the command to the object level and added an
   optional standard attribute to the command element.  Also updated
   section 3.1 for clarity on name attribute; updated section 3.9 for
   clarity on uses of <fee:reason>; removed second paragraph in section
   5.2.1 as it was duplicative of second to last paragraph in 4.0; and
   updated section 5.1.1 to add section references.

11.13.  Change from 07 to 08

   Updated section 3.8 and 5.1.1 to provide clarity on server processing
   and response of various scenarios (i.e. "quiet" period processing).

11.14.  Change from 06 to 07

   Updated section 3.8 and 4.0 to provide clarity on server processing
   and response of various scenarios.

11.15.  Change from 05 to 06

   Updated scheme to version 0.23 to allow the return of no
   <fee:command> element(s) if an error situation occurs.  Edited
   section 3.8 extensively after input from interim meeting and REGEXT
   F2F meeting at IETF-99.  Added normative reference for draft-ietf-
   eppext-launchphase.

11.16.  Change from 04 to 05

   Updated scheme to version 0.21 to support the lang attribute for the
   reason element of the objectCDType and the commandType types as well
   as to add the update command to the commandEnum type.  Updated
   section 3.1 to include language for the custom command.  Added
   section 3.9 to provide a description of the <fee:reason> element.
   Fixed typos and added clarification text on when client fee is less
   than server fee in section 4.  Additionally, I added description
   pointers to appropriate Section 3 definitions for element clarity
   throughout the document.

11.17.  Change from 03 to 04

   Updated scheme to version 0.19 to correct typos and to replace the
   commandTypeValue type with the commandEnum type and customName
   attribute for stricter validation.  Updated various text for grammar
   and clarity.  Added text to section 4 clarifying the <check> response
   when the client provided no fee extension but the server was
   expecting the extension.

11.18.  Change from 02 to 03

   Updated scheme to version 0.17 to simplify the check command syntax.
   Moved fee avail to objectCDType to allow fast failing on error
   situations.  Removed the objectCheckType as it was no longer being
   used.  Updated examples to reflect these scheme changes.  Added
   language for server failing a <create> if the <fee:fee> passed by the
   client is less than the server fee.

11.19.  Change from 01 to 02

   Updated scheme to version 0.15 to fix errors in CommandType,
   objectCDType, transformCommandType and transformResultType
   definitions.

11.20.  Change from 00 to 01

   Added Roger Carney as author to finish draft.  Moved Formal Syntax
   section to main level numbering.  Various grammar, typos, and
   administrative edits for clarity.  Removed default value for the
   "applied" attribute of <fee:fee> so that it can truly be optional.
   Added support for the <delete> command to return a <fee:fee> element
   as well.  Modified default response on the <check> command for the
   optional <fee:period> when it was not provided in the command,
   leaving it to the server to provide the default period value.
   Extensive edits were done to the <check> command, the <check>
   response and to the fee extension schema (checkType, objectCheckType,
   objectIdentifierType, objectCDType, commandType) to support
   requesting and returning multiple transformation fees in a single
   call.  Added section on Phase/Subphase to provide more context on the
   uses.

11.21.  Change from draft-brown-00 to draft-ietf-regext-fees-00

   Updated to be REGEXT WG document.

12.  References

12.1.  Normative References

   [ISO4217:2015]
              International Organization for Standardization, "Codes for
              the representation of currencies", August 2015,
              <https://www.iso.org/standard/64758.html>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", Identifying
              Languages", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC3915]  Hollenbeck, S., "Domain Registry Grace Period Mapping for
              the Extensible Provisioning Protocol (EPP)", 47, RFC 3915, 5646, DOI 10.17487/RFC3915, 10.17487/RFC5646,
              September 2004,
              <https://www.rfc-editor.org/info/rfc3915>. 2009, <https://www.rfc-editor.org/info/rfc5646>.

   [RFC5730]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
              STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009,
              <https://www.rfc-editor.org/info/rfc5730>.

   [RFC5731]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)
              Domain Name Mapping", STD 69, RFC 5731,
              DOI 10.17487/RFC5731, August 2009,
              <https://www.rfc-editor.org/info/rfc5731>.

   [RFC7942]  Sheffer, Y. and A. Farrel, "Improving Awareness of Running
              Code: The Implementation Status Section", BCP 205,
              RFC 7942, DOI 10.17487/RFC7942, July 2016,
              <https://www.rfc-editor.org/info/rfc7942>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8334]  Gould, J., Tan, W., and G. Brown, "Launch Phase Mapping
              for the Extensible Provisioning Protocol (EPP)", RFC 8334,
              DOI 10.17487/RFC8334, March 2018,
              <https://www.rfc-editor.org/info/rfc8334>.

   [W3C.REC-xmlschema-1-20041028]
              Thompson, H., Beech, D., Maloney, M., and N. Mendelsohn,
              "XML Schema Part 1: Structures Second Edition", World Wide
              Web Consortium Recommendation REC-xmlschema-1-20041028,
              October 2004,
              <http://www.w3.org/TR/2004/REC-xmlschema-1-20041028>.

12.2.

9.2.  Informative References

   [RFC7451]  Hollenbeck, S., "Extension Registry for the Extensible
              Provisioning Protocol", RFC 7451, DOI 10.17487/RFC7451,
              February 2015, <https://www.rfc-editor.org/info/rfc7451>.

Acknowledgements

   The authors wish to thank the following persons for their feedback
   and suggestions:

   *  James Gould of Verisign Inc.
   *  Luis Munoz of ISC
   *  Michael Young
   *  Ben Levac
   *  Jeff Eckhaus
   *  Seth Goldman of Google
   *  Klaus Malorny and Michael Bauland of Knipp
   *  Jody Kolker, Joe Snitker, and Kevin Allendorf of GoDaddy
   *  Michael Holloway of Com Laude
   *  Santosh Kalsangrah of Impetus Infotech
   *  Alex Mayrhofer of Nic.at
   *  Thomas Corte of Knipp Medien und Kommunikation GmbH

Authors' Addresses

   Roger Carney
   GoDaddy Inc.
   14455 N. Hayden Rd. #219
   Scottsdale, AZ 85260
   US
   United States of America

   Email: rcarney@godaddy.com
   URI:   http://www.godaddy.com

   Gavin Brown
   CentralNic Group plc
   35-39 Moorgate
   London, England
   London
   EC2R 6AR
   GB
   United Kingdom

   Phone: +44 20 33 88 0600
   Email: gavin.brown@centralnic.com
   URI:   http://www.centralnic.com

   Jothan Frakes

   Email: jothan@jothan.com
   URI:   http://jothan.com