INTERNET-DRAFT C. Apple AT&T Laboratories Expires: May 17, 1998 17 November 1997 Directory Schema Listing Meta Data Status of this Memo This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as ``work in progress.'' To learn the current status of any Internet-Draft, please check the ``1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe), munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or ftp.isi.edu (US West Coast). Abstract This memo defines a MIME directory profile for content transfer and encoding of meta data elements used for cataloging schema listings in a directory schema listing service. 1.0 Introduction The fastest route to interoperable directory services is through standard object classes and attribute types. There is a growing number of places where schema for Internet Directory Services and Internet Operations are being defined, with varying degrees of documentation. This plethora of schema is unavoidable in the light of the needs of different service communities, but it makes it difficult for directory service builders to find and make use of an existing schema that will serve their needs and increase interoperability with other systems. A listing service providing a single point of discovery for directory service schema will promote schema reuse, reduce duplication of effort, and thus promote directory service interoperability. Meta data will be used to catalog Apple [Page 1] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 and distinguish schema listings in this service. This document defines a [MIMEDIR] profile for meta data content transfer and encoding. 1.1 Terms and Definitions Information Object - a descriptive abstraction of some real-world object Schema - a collection of definitions for related information objects Listing Meta Data - characteristics that differentiate one schema from another; used to catalog schema Listing Content - a formal specification of a schema using a profile of [MIMEDIR] Schema Listing - the combination of listing meta data and all available listing content for a particular schema Repository - a database in which schema listings are stored Schema Listing Request - a schema listing formatted using [MIME] constructs that is submitted for consideration as a schema listing to be published in a repository Operator - an organization that administers and maintains a repository Primary Repository - the repository that masters the schema listings database Shadow Repository - a repository that mirrors the primary repository Contact Person - the name of the individual who holds the authority to update a schema listing and who should be contacted if questions or concerns arise related to a schema listing or schema listing request Listing Authority Contact - the name of the individual who holds authority to replace a contact person; can be either the contact person for a schema listing or an alternate contact within the organization to which the contact person belongs (this allows one person organizations to list schema) The terms for specifying requirement level described in [RFC2119] are used in this document. Apple [Page 2] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 2.0 The "schema-metadata-0" MIME Directory Profile Registration This profile is identified by the following registration template information. To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME profile "schema-metadata-0" Profile Name: schema-metadata-0 Profile Purpose: To represent meta data for a schema listing stored in the repository or a schema listing request under community review. Profile Types: listingName, schemaTitle, schemaUse, availableProfile, relatedTo, contactLanguage, contactName, contactEmail, contactPhone, contactAddress, authLanguage, authName, authEmail, authPhone, authAddress, contentURL, security, created, moreInfo, caveat, listingComments Profile Special Notes: The charset parameter MUST be present in the MIME content header and the value of this parameter MUST be "utf-8". Neither the "BEGIN", "END", nor "SOURCE" type is used in the contents of this profile. Type grouping is not used in the contents of this profile. Each MIME Directory Type Registration that follows in section 3 of this document includes a specification of whether or not a particular type is constrained to be single-valued or permitted to be multi-valued. Types that are permitted to be multi-valued MUST have at least one value, unless otherwise noted in the 'Type special notes' component of a type definition. Implementors should note that there will likely be values of profile types in some contents much longer than 76 bytes. In addition, there may be non-ASCII characters and embedded CRLFs inside of values, which could require either quoting of the value or use of a content transfer encoding. The following types MUST be included by schema writers in all schema listing requests: listingName, schemaTitle, schemaUse, availableProfile, contactLanguage, contactName, contactEmail, Apple [Page 3] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 contactPhone, contactAddress, authLanguage, authName, authEmail, authPhone, authAddress, moreInfo, and security. The 'listingName' type value provided by the schema writer is temporary and only intended for use during the schema listing request review period. The permanent 'listingName' type value MUST be created by the primary listing repository operator. The 'relatedTo' type value MUST be provided by the schema writer as a part of the schema listing request if the schema listing proposed in the request has a relationship to published schema listings and/or other schema listing requests being review. If one or more schema writers are submitting a set of related schema listing requests in parallel, the production of the 'relatedTo' type value MUST be used, rather than the production. The following types MUST be provided by the primary schema listing repository operator and MUST NOT be accepted from the schema writer: contentURL, created, and listingComments. Intended Usage: COMMON 3.0 MIME Directory Type Registrations This document defines all types use in the schema-metadata-0 profile. These types are intended for use in the "schema-metadata-0" profile, although they may be applicable to other profiles defined in the future. 3.1 listingName To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type listingName Type name: listingName Type purpose: To represent a globally unique identifier for the schema listing name. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): Apple [Page 4] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 name = permanent / temp permanent = oid "." sequence "." version ; a permanent schema listing name assigned ; the primary listing repository operator oid = oid-component *("." oid-component) oid-component = 1*DIGIT DIGIT = sequence = NZDIGIT *DIGIT NZDIGIT = version = version-component *("." version-component) version-component = 1*DIGIT temp = ("x-" / "X-") (oid/guid) ; a temporary schema listing request ; name assigned by a schema writer during ; creation of a listing request guid = Type special notes: This type MUST be single-valued. A language parameter MUST NOT be used with this type. For published schema listings, a value of this type is an OID constructed by the primary listing repository operator based on a root OID administered by the operator, a listing sequence number generated by the operator, and a listing version number assigned by the operator. For schema listing requests a value of this type is an OID assigned by or a GUID generated by the schema writer creating the request with an appropriate prefix to indicate that it is a temporary schema listing name. 3.2 schemaTitle To: ietf-mime-direct@imc.org Apple [Page 5] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 Subject: Registration of text/directory MIME type schemaTitle Type name: schemaTitle Type purpose: To represent a real world title of a listed schema. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): utf8-text = 1* Type special notes: This type MAY be multi-valued. A language parameter MUST be used with this type. A value of this type MAY contain local or native version numbers or other version indicators for listed schema. Such schema version information MUST be treated as opaque by implementors. 3.3 schemaUse To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type schemaUse Type name: schemaUse Type purpose: To represent a statement of intended use for a listed schema. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): utf8-text = 1* Type special notes: This type MAY be multi-valued. A language parameter MUST be used with this type. A value of this type is an in-line text description of the intended Apple [Page 6] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 use of a listed schema and MAY include embedded CRLF characters. 3.4 availableProfile To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type availableProfile Type name: availableProfile Type purpose: To represent a file name in the schema listing repository for an available schema specification constructed using an appropriate profile of [MIMEDIR]. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): profile = ; all [FILESYN] values except "metadata" ; MAY be used to construct values Type special notes: This type MAY be multi-valued. A language parameter MUST NOT be used with this type. Currently, there are three [MIMEDIR] profiles defined for containing schema specifications: [MIMELDAP], [MIMEWHOIS], and [MIMERWHOIS]. Additional profiles may be defined in other documents. Each of these profiles is identified by a sort text string representative of the profile name. 3.5 relatedTo To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type relatedTo Type name: relatedTo Type purpose: To represent an indication of a relationship of published schema listing or schema listing request with another published schema listing or schema listing request. Type encoding: 8bit Apple [Page 7] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): related = (md-filename / req-filename) *SPACE "$" *SPACE related-option md-filename = req-filename = related-option = "obsoletes" / "obsoleted-by" / "updates" / "inherits" / vendor-option vendor-option = ("x-" / "X-") vendor-name "-" vendor-specific-relationship vendor-name = 1*TOKEN vendor-specific-relationship = 1*TOKEN TOKEN = CHAR = specials = "(" / ")" / "<" / ">" / "@" ; MUST be in quoted- / "," / ";" / ":" / "\" / <"> ; string, to use / "." / "[" / "]" ; within a word <"> = SPACE = CRLF = CR LF CR = LF = CTL = Type special notes: This type MAY be multi-valued. If a schema listing is related to different schema listing, this type is REQUIRED, otherwise the use of this type is OPTIONAL. Apple [Page 8] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 A language parameter MUST NOT be used with this type. This type is used to indicate relationships between published schema listings and schema listing requests as well as between one or more schema listing requests being submitted for review in parallel. Examples of such relationships include deprecation, revision, inheritance, and those specific to a particular vendor. If a schema listing request is related to another request, a value of this type MUST be assigned a temporary value relavent to the related request by the schema writer. Temporary values of this type MUST be subsequently replaced with a permanent value by the primary listing repository operator prior to publication of the listing. 3.6 contactLanguage To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type contactLanguage Type name: contactLanguage Type purpose: To represent a language understood by the contact person, organization, or role for a schema listing. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): c-lang = Type special notes: This type MAY be multi-valued. A language parameter MUST NOT be used with this type. 3.7 contactName To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type contactName Type name: contactName Type purpose: To represent the name of the contact person, organization, or role for a schema listing. Apple [Page 9] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): utf8-text = 1* Type special notes: This type MUST be single-valued. A language parameter MUST NOT be used with this type. 3.8 contactEmail To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type contactEmail Type name: contactEmail Type purpose: To represent the electronic mail address of the contact person, organization, or role for a schema listing. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): c-email = local-part "@" domain-part domain-part = sub-domain *("." sub-domain) sub-domain = 1* CHAR = specials = "(" / ")" / "<" / ">" / "@" ; MUST be in quoted- / "," / ";" / ":" / "\" / <"> ; string, to use / "." / "[" / "]" ; within a word <"> = SPACE = CRLF = CR LF CR = Apple [Page 10] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 LF = CTL = Type special notes: This type MUST be single-valued. A language parameter MUST NOT be used with this type. 3.9 contactPhone To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type contactPhone Type name: contactPhone Type purpose: To represent the voice telephone number of the contact person, organization, or role for a schema listing. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): c-phone = 1* ; MUST use full international form (e.g., +1 908 582 2409) CHAR = CRLF = CR LF CR = LF = CTL = Type special notes: This type MUST be single-valued. A language parameter MUST NOT be used with this type. 3.10 contactAddress To: ietf-mime-direct@imc.org Apple [Page 11] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 Subject: Registration of text/directory MIME type contactAddress Type name: contactAddress Type purpose: To represent the postal address of the contact person, organization, or role for a schema listing. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): c-addr = postal-string *5(*SPACE "$" *SPACE postal-string) postal-string = 1* SPACE = Type special notes: This type MUST be single-valued. A language parameter MUST NOT be used with this type. 3.11 authLanguage To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type authLanguage Type name: authLanguage Type purpose: To represent the language understood by the listing authority contact for a schema listing. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): lac-lang = Type special notes: This type MAY be multi-valued A language paramter MUST NOT be used with this type. Apple [Page 12] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 3.12 authName To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type authName Type name: authName Type purpose: To represent the name of the listing authority contact for a schema listing. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): utf8-text = 1* Type special notes: This type MUST be single-valued. A language parameter MUST NOT be used with this type. The value of this type MAY be identical to the value of the 3.13 authEmail To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type authEmail Type name: authEmail Type purpose: To represent the electronic mail address of the listing authority contact for a schema listing. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): c-email = local-part "@" domain-part domain-part = sub-domain *("." sub-domain) sub-domain = 1* Apple [Page 13] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 CHAR = specials = "(" / ")" / "<" / ">" / "@" ; MUST be in quoted- / "," / ";" / ":" / "\" / <"> ; string, to use / "." / "[" / "]" ; within a word <"> = SPACE = CRLF = CR LF CR = LF = CTL = Type special notes: This type MUST be single-valued. A language parameter MUST NOT be used with this type. The value of this type MAY be identical to the value of the 3.14 authPhone To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type authPhone Type name: authPhone Type purpose: To represent the voice telephone number of the listing authority contact for a schema listing. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): lac-phone = 1* ; MUST use full international form (e.g., +1 908 582 2409) CHAR = CRLF = CR LF Apple [Page 14] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 CR = LF = CTL = Type special notes: This type MUST be single-valued. A language parameter MUST NOT be used with this type. The value of this type MAY be identical to the value of the 3.15 authAddress To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type authAddress Type name: authAddress Type purpose: To represent the postal address of the listing authority contact for a schema listing. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): lac-addr = postal-string *5(*SPACE "$" *SPACE postal-string) postal-string = 1* SPACE = Type special notes: This type MUST be single-valued. A language parameter MUST NOT be used with this type. The value of this type MAY be identical to the value of the 3.16 contentURL To: ietf-mime-direct@imc.org Apple [Page 15] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 Subject: Registration of text/directory MIME type contentURL Type name: contentURL Type purpose: To represent a URL corresponding to an available profile of a schema listing. Type encoding: 8bit Type valuetype: uri, formatted as a URL [RFC1738]. Type special notes: This type MAY be multi-valued. A language parameter MUST NOT be used with this type. 3.17 security To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type security Type name: security Type purpose: To represent a description of security considerations for a single available profile of listing content. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): utf8-text = 1* Type special notes: This type MAY be multi-valued. This type MUST have at least one value for each available profile. A language parameter MUST be used with this type. A value of this type is an in-line text description of security considerations for a single available profile of a listed schema and MAY include embedded CRLF characters. Apple [Page 16] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 3.18 created To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type created Type name: created Type purpose: To represent the date and time at which a schema listing was published. Type encoding: 8bit Type valuetype: date-time, with the following syntax (specified using the BNF in [RFC822]): created = date "T" time "Z" date = 4DIGIT "-" 2DIGIT "-" 2DIGIT ; year-month-day ; e.g., 1997-08-27 time = 2DIGIT ":" 2DIGIT ":" 2DIGIT ; hh:mm:ss ; e.g., 00:00:00 thru 23:59:59 ; MUST be based on GMT DIGIT = Type special notes: This type MUST be single-valued. A language parameter MUST NOT be used with this type. 3.19 moreInfo To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type moreInfo Type name: moreInfo Type purpose: To represent a labeled reference to external content (not stored in the schema listing repository) related to a schema listing. Type encoding: 8bit Apple [Page 17] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): more = uri *SPACE "(" label ")" ; MAY be multi-valued or single-valued uri = ; in this case the URI is constrained to ; be a URL as specified in [RFC1738] label = option [*SPACE "$" *SPACE checksum] ; only one option is allowed per instance ; of this multi-valued meta data element option = "opaque-schema" / "copyright" / "licensing" / "general" / "image" ; this set of options is intended for use in the initial release ; of the schema listing service additional options may be ; defined in other documents ; "opaque-schema" signifies that a profile of [MIMEIR] or other ; syntax specification for a schema is being referenced checksum = > ; the MD5 checksum MUST be generated in according to ; [GUIDGEN] or [GUIDOTHER] Type special notes: This type MAY be multi-valued. A language parameter MUST be used with this type. The use of this type is REQUIRED if a schema writer wishes to include references to external content related to a schema listing. Otherwise, this type MUST NOT be used in forming schema listing requests or published schema listings. The rationale for including these external references MAY be related to extensive copyright or right-to-use statements, a requirement external to the schema listing service for vendor branding of a listed schema, or a schema specification of a form not expressable using a [MIMEDIR] profile currently supported by the schema listing service. 3.20 caveat To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type caveat Apple [Page 18] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 Type name: caveat Type purpose: To represent a caveat explaining that content obtained by following external references to information not stored in the schema listing repository is outside of the control of the repository. Type encoding: 8bit Type valuetype: text, consisting of the following in-line text value: Information obtained by following external content references expressed using the moreInfo type are outside of the control of the schema listing service operators. Users of this information should be aware that it is possible for this information to change after the referencing schema listing has been published. Type special notes: This type MAY be multi-valued. A language parameter MUST be used with this type. The use of this type is REQUIRED if a schema writer wishes to include references to external content related to a schema listing. Otherwise, this type MUST NOT be used in forming schema listing requests or published schema listings. 3.21 listingComments To: ietf-mime-direct@imc.org Subject: Registration of text/directory MIME type listingComments Type name: listingComments Type purpose: To represent which will be attached to a schema listing. Type encoding: 8bit Type valuetype: text, with the following syntax (specified using the BNF in [RFC822]): utf8-text = 1* Apple [Page 19] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 Type special notes: This type MAY be multi-valued. A language parameter MUST be used with this type. The use of this type is REQUIRED if during review of a schema listing request, the primary listing repository operator is asked by the reviewers to include particular comments or generic caveats with a schema listing prior to publication. Values of this type are in-line text comments or generic caveats associated with a schema listing and MAY include embedded CRLF characters. 4.0 Examples 4.1 Listing Request Use of Profile From: Whomever@wherever.com To: Someone@somewhere.com Subject: schema listing request MIME-Version: 1.0 Message-Id: Content-Type: text/directory; profile="schema-metadata-0"; charset="utf-8" Content-Transfer-Encoding: Quoted-Printable listingName: x-1.1.1 schemaTitle;language=en: Some Schema Title V1.0 schemaUse;language=en: Intended as an example. availableProfile: schema-ldap-0 contactLanguage: en contactName: Whome Ever contactEmail: Whomever@wherever.com contactPhone: +1 908 555 1212 contactAddress: Some Street $ Some City $ Some State $ Some Country authLanguage: en authName: Whome Ever authEmail: Whomever@wherever.com authPhone: +1 908 555 1212 authAddress: Some Street $ Some City $ Some State $ Some Country moreInfo: http://www.wherever.com/schema/= (opaque-schema $ ) caveat: Information obtained by following external content=0D=0A= references expressed using the moreInfo type are=0D=0A= outside of the control of the schema listing service=0D=0A= Apple [Page 20] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 operators. Users of this information should be aware=0D=0A= that it is possible for this information to change=0D=0A= after the referencing schema listing has been=0D=0A= published. security;language=en: A security analysis was not performed. relatedTo: schema-metadata-1.0 $ obsoletes 4.2 Published Schema Listing Use of Profile Content-Type: text/directory; profile="schema-metadata-0"; charset="utf-8" Content-Transfer-Encoding: Quoted-Printable listingName: 1.1.0 schemaTitle;language=en: Some Schema Title V1.0 schemaUse;language=en: Intended as an example. availableProfile: schema-ldap-0 contactLanguage: en contactName: Whome Ever contactEmail: Whomever@wherever.com contactPhone: +1 908 555 1212 contactAddress: Some Street $ Some City $ Some State $ Some Country authLanguage: en authName: Whome Ever authEmail: Whomever@wherever.com authPhone: +1 908 555 1212 authAddress: Some Street $ Some City $ Some State $ Some Country moreInfo: http://www.wherever.com/schema/= (opaque-schema $ ) caveat: Information obtained by following external content=0D=0A= references expressed using the moreInfo type are=0D=0A= outside of the control of the schema listing service=0D=0A= operators. Users of this information should be aware=0D=0A= that it is possible for this information to change=0D=0A= after the referencing schema listing has been=0D=0A= published. relatedTo: schema-metadata-1.0 $ obsoletes security;language=en: A security analysis was not performed. contentURL: ftp://ftp.somewhere.com/schema/1/1/schema-ldap-1.1 created: 1997-11-17T15:21:00Z listingComments: This listing is only an example. 5.0 Security Considerations The text/directory profile defined in this document does not provide any method for carrying authentication information. Apple [Page 21] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 The text/directory profile defined in this document allows content external to any schema listing service repository to be referenced in the schema listing and includes an MD5-based fingerprint of the refernced content itself. Users of the schema listing service SHOULD take steps to verify that this external information has not changed since schema listing publication. Users should also be aware that such external content is outside of the control of the schema listing service operators. A MIME body part containing contents structured according to the text/directory profile defined in this document MAY be incorporated in a digitally signed MIME content, which can be used to verify that the body part has not been modified during transit. If a signer has been certified by a trusted third party, it may also be possible to verify the origin of the content. 6.0 Acknowledgements The engineering team for listing service requirements: Chris Apple - AT&T Labs Sanjay Jain - Oracle Michael Mealling - NSI John Strassner - Cisco Sam Sun - CNRI Mark Wahl - Critical Angle Chris Weider - Microsoft 7.0 References [FILESYN] C. Apple, "Directory Schema Listing File Name Syntax", INTERNET-DRAFT , October 1997. [GUIDGEN] P. Leach, R. Salz, "UUIDs and GUIDs", INTERNET-DRAFT , Feb. 1997. [GUIDOTHER] Open Group CAE Specification C309 "DCE: Remote Procedure Call", Aug. 1994. [MIME] [RFC2045], [RFC2046], and [RFC2047]. [MIMEDIR] T. Howes, M. Smith, "A MIME Content-Type for Directory Information", INTERNET-DRAFT , July 1997. [RFC822] D. Crocker, "Standard of the Format of ARPA-Internet Text Messages", STD 11, RFC 822, August 1982. Apple [Page 22] INTERNET-DRAFT Directory Schema Listing Meta Data 17 November 1997 [RFC1321] R. Rivest, "The MD5 Message-Digest Algorithm", RFC 1321, April 1992. [RFC1738] T. Berners-Lee, L. Masinter, M. McCahill, "Uniform Resource Locators", RFC 1738, December 1994. [RFC1766] H. Alvestrand, "Tags for the Identification of Languages", RFC 1766, March 1995. [RFC2119] S. Bradner, "Key words for use in RFCs to Indicate Requirement Level", March 1997. [RFC2044] F. Yergeau, "UTF-8, a transformation format of Unicode and ISO 10646", RFC 2044, October 1996. [RFC2045] N. Freed, N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996. [RFC2046] N. Freed & N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types", RFC 2046, November 1996. [RFC2047] K. Moore, "MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text", RFC 2047, November 1996. 8.0 Author's Address Chris Apple AT&T Laboratories 600 - 700 Mountain Ave., Room 2F-165 Murray Hill, NJ 07974-0636 USA E-Mail: capple@att.com Phone: +1 908 582 2409 FAX: +1 908 582 3296 This INTERNET-DRAFT expires on May 17, 1998. Apple [Page 23]