IMAP Extensions Working Group R. Gellens Internet Draft: IMAP ANNOTATE Extension C. Daboo Document: draft-ietf-imapext-annotate-02.txt November 2001 IMAP ANNOTATE Extension Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet- Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Copyright Notice Copyright (C) The Internet Society 2001. All Rights Reserved. Gellens & Daboo Expires May 2002 [Page 1] Internet Draft IMAP ANNOTATE Extension November 2001 Table of Contents 1 Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 2 3 Conventions Used in This Document . . . . . . . . . . . . . . 2 4 Document Meta-Data . . . . . . . . . . . . . . . . . . . . . 3 4.1 Open Issues . . . . . . . . . . . . . . . . . . . . . . . 3 4.2 Change History . . . . . . . . . . . . . . . . . . . . . 3 5 Introduction and Overview . . . . . . . . . . . . . . . . . . 4 6 Data Model . . . . . . . . . . . . . . . . . . . . . . . . . 4 6.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . 4 6.2 Namespace of Entries and Attributes . . . . . . . . . . 5 6.2.1 Entry Names . . . . . . . . . . . . . . . . . . . . . 5 6.2.2 Attribute Names . . . . . . . . . . . . . . . . . . 7 7 Private versus Shared . . . . . . . . . . . . . . . . . . . . 8 8 IMAP Protocol Changes . . . . . . . . . . . . . . . . . . . 9 8.1 ANNOTATION Message Data Item in FETCH Command . . . . . . 9 8.2 ANNOTATION Message Data Item in FETCH Response . . . . . 10 8.3 ANNOTATION Message Data Item in STORE . . . . . . . . . . 11 8.4 ANNOTATION Message Data Item in APPEND . . . . . . . . . 13 8.5 ANNOTATION Criterion in SEARCH . . . . . . . . . . . . . 13 8.6 ANNOTATION Key in SORT . . . . . . . . . . . . . . . . . 14 8.7 ACL Rights . . . . . . . . . . . . . . . . . . . . . . . 15 9 Interaction with MODTIME . . . . . . . . . . . . . . . . . . 15 10 Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . . 15 11 IANA Considerations . . . . . . . . . . . . . . . . . . . . 16 11.1 Entry and Attribute Registration Template . . . . . . . . 16 12 Security Considerations . . . . . . . . . . . . . . . . . . 17 13 References . . . . . . . . . . . . . . . . . . . . . . . . . 17 14 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 18 15 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 18 16 Full Copyright Statement . . . . . . . . . . . . . . . . . . 18 1 Abstract The ANNOTATE extension to the Internet Message Access Protocol [IMAP4] permits clients and servers to maintain "metadata" for messages stored in an IMAP4 mailbox. 2 Discussion Public comments can be sent to the IETF IMAP Extensions mailing list, . To subscribe, send a message to with the word SUBSCRIBE as the body. Private comments should be sent to the authors. 3 Conventions Used in This Document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [KEYWORDS]. Gellens & Daboo Expires May 2002 [Page 2] Internet Draft IMAP ANNOTATE Extension November 2001 Formal syntax is defined using ABNF [ABNF] as modified by [IMAP4]. In examples, "C:" and "S:" indicate lines sent by the client and server respectively. Line breaks not preceded by a "C:" or "S:" are for editorial clarity only. 4 Document Meta-Data 4.1 Open Issues At points in this document open issues are discussed, marked by the text "<<>>". These are items which have not been finalized. Discussion and comment is requested. Please use the IETF IMAP Extensions mailing list, as described in section 2. 4.2 Change History Changes from -01 to -02: 1. Now require .pric or .shared on store operations. Changes from -00 to -01: 1. MODTIME moved to its own draft, which this draft now depends on. Thus, Conditional Annotation STORE and related items deleted from this draft. 2. Private versus Shared Annotations: both are possible (separately addressable using ".priv" and ".shared" suffixes). There is a per-mailbox setting for the default. It is an open issue how this is viewed or changed by the client. 3. In ACLs, the "w" right is needed to updated shared state; the "s" right is needed to update private state. 4. Various clarifications and text modifications. 5. Added 'forwarded' flag for message parts. Changes from pre-imapext to -00: 1. Clarified text describing attributions, entries, and attributes. 2. Changed 'modifiedsince' to 'modtime'; referenced ACAP spec. 3. Deleted 'queued' flag. 4. Expanded and explained smtp-envelope entry. 5. Restricted including ANNOTATION data in unsolicited responses until the client uses it first. (Open issue as to if needed). 6. Examples now only use valid entries and attributes. 7. Updated Security Considerations. 8. Content-Type now defaults to text/plain. 9. Open Issue: Shared vs. private annotations. 10. Open issue: Annotation Modtime untagged response or VALIDTIME FETCH data. 11. Open issue: Conditional annotation STORE. 12. ANNOTATION criterion available if both "ANNOTATE" and "SORT" in CAPABILITY command response. Gellens & Daboo Expires May 2002 [Page 3] Internet Draft IMAP ANNOTATE Extension November 2001 13. Prohibition on annotations in lieu of base spec functionality. 14. Specified required ACL rights. 15. ANNOTATION message data item in APPEND. 16. ANNOTATION-MODTIME message data item in STATUS. 17. Replaced ATOM_CHAR with utf8-char. 18. Updated other ABNF entries. 5 Introduction and Overview The ANNOTATE extension is present in any IMAP4 implementation which returns "ANNOTATE" as one of the supported capabilities in the CAPABILITY command response. The ANNOTATE extension adds a new message data item to the FETCH and STORE commands, as well as adding SEARCH and SORT keys and APPEND and STATUS modifiers. This extension makes the following changes to the IMAP4 protocol: a) adds a new ANNOTATION message data item for use in FETCH b) adds a new ANNOTATION message data item for use in STORE c) adds a new ANNOTATION search criterion for use in SEARCH d) adds a new ANNOTATION sort key for use in SORT extension e) adds a new ANNOTATION data item for use in APPEND The data model used for the storage of annotations is based on that of the Application Configuration Access Protocol [ACAP]. Note that there is no inheritance in annotations. Clients MUST NOT use annotations in lieu of equivalent IMAP base specification facilities. For example, use of a "seen" flag in the vendor namespace together with ".PEEK" in fetches. Such behavior would significantly reduce IMAP interoperability. <<>> A possible exception to this rule is the potential use of annotation flags in lieu of or as an alternate means of accessing IMAP flags. The rest of this document describes the data model and protocol changes more rigorously. 6 Data Model 6.1 Overview The data model used in ANNOTATE is that of a uniquely named entry which contains a set of standard attributes. A single coherent unit of "metadata" for a message is stored as a single entry, made up of several attributes. Gellens & Daboo Expires May 2002 [Page 4] Internet Draft IMAP ANNOTATE Extension November 2001 For example, a comment added to a message has an entry name of "/message/comment". This entry is composed of several attributes such as "value", "modtime", etc. which contain the properties and data of the entry. The protocol changes to IMAP described below allow a client to access or change the values of any attributes in any entries in a message annotation, assuming it has sufficient access rights to do so (see section 8.7 for specifics). 6.2 Namespace of Entries and Attributes Each message annotation is made up of a set of entries. Each entry has a hierarchical name in UTF-8, with each component of the name separated by a slash ("/"). Each entry is made up of a set of attributes. Each attribute has a hierarchical name in UTF-8, with each component of the name separated by a period ("."). The value of an attribute is NIL (has no value), or is a string of zero or more octets. Entry and attribute names MUST NOT contain asterisk ("*") or percent ("%") characters and MUST be valid UTF-8 strings which do not contain the NULL octet. Invalid entry or attribute names result in a BAD response in any IMAP commands where they are used. Use of non-visible UTF-8 characters in entry and attribute names is strongly discouraged. This specification defines an initial set of entry and attribute names available for use in message annotations. In addition, an extension mechanism is described to allow additional names to be added for extensibility. 6.2.1 Entry Names Entry names MUST be specified in a standards track or IESG approved experimental RFC, or fall under the vendor namespace. See section 11.1 for the registration template. /message Defines the top-level of entries associated with an entire message. This entry itself does not contain any attributes. /message/comment Defines a comment or note associated with an entire message. Gellens & Daboo Expires May 2002 [Page 5] Internet Draft IMAP ANNOTATE Extension November 2001 /message/flags Defines the top-level of entries for client-use flags associated with an entire message. All sub-entries are maintained entirely by the client. There is no implicit change to any flag by the server. /message/flags/redirected /message/flags/forwarded Defines client-use flags for an entire message. The "value" attribute of these entries must be either "1", "0" or NIL. The 'redirected' flag indicates that a message has been handed off to someone else, by resending the message with minimal alterations, and in such a way that a reply by the new recipient is addressed to the original author, not the user who performed the redirection. The 'forwarded' flag indicates the message was resent to another user, embedded within or attached to a new message. /message/smtp-envelope Defines the top-level of entries which together describe the SMTP envelope used in delivery of the message. There are no attributes at this level. The client SHOULD NOT modify the /message/smtp-envelope entry or any sub-entries or any of their attributes, except in messages which have the DRAFT flag set. /message/smtp-envelope/from /message/smtp-envelope/to /message/smtp-envelope/orcpt /message/smtp-envelope/envid Contains the properties of the SMTP envelope: 'from' is the return-path of the message; 'to' is the recipient of the message. 'orcpt' and 'envid' contain the original recipient and envelope ID as specified in [SMTP-DSN]. /message/subject Contains text supplied by the message recipient, to be used by the client instead of the original message Subject. /message/vendor/ Defines the top-level of entries associated with an entire message as created by a particular product of some vendor. These sub-entries can be used by vendors to provide client-specific attributes. The vendor-token MUST be registered with IANA. /body/ Defines the top-level of entries associated with a specific body part of a message. This entry itself does not contain any attributes. The part-specifier uses the same part specifier syntax as the BODY message data item in the FETCH command [IMAP4]. Gellens & Daboo Expires May 2002 [Page 6] Internet Draft IMAP ANNOTATE Extension November 2001 /body//comment Defines a comment or note associated with a specific body part of a message. /body//flags Defines the top-level of entries associated with flag state for a specific body part of a message. All sub-entries are maintained entirely by the client. There is no implicit change to any flag by the server. /body//flags/seen /body//flags/answered /body//flags/flagged /body//flags/forwarded Defines flags for a specific body part of a message. The "value" attribute of these entries must be either "1", "0" or NIL. /body//vendor/ Defines the top-level of entries associated with a specific body part of a message as created by a particular product of some vendor. This entry can be used by vendors to provide client specific attributes. The vendor-token MUST be registered with IANA. 6.2.2 Attribute Names Attribute names MUST be specified in a standards track or IESG approved experimental RFC, or fall under the vendor namespace. See section 11.1 for the registration template. All attribute names implicitly have a ".priv" and a ".shared" suffix which maps to private and shared versions of the entry. Searching or fetching without using either suffix includes both. Storing without using either suffix stores into the default. The default is set per-mailbox. See section 7 for more information. value The data value of the attribute. size The size of the value, in octets. Set automatically by the server, read-only to clients. modtime An opaque value set by the server when this entry is modified. It can be used by the client to request notification of which entries have changed relative to that of a known entry. In addition to its use in disconnected/synchronization operations, it can also be helpful in determining which entries have changed while a client is connected. (The value is intended to be used Gellens & Daboo Expires May 2002 [Page 7] Internet Draft IMAP ANNOTATE Extension November 2001 only for comparisons within a server, not as an accurate timestamp.) It is described more fully in section 3.1.1 of [ACAP]. content-type A MIME [MIME] content type and subtype that describes the nature of the content of the "value" attribute. If not present, a value of "text/plain; charset=utf8" is assumed. vendor. Defines an attribute associated with a particular product of some vendor. This attribute can be used by vendors to provide client specific attributes. The vendor-token MUST be registered with IANA. 7 Private versus Shared Some IMAP mailboxes are private, accessible only to the owning user. Other mailboxes are not, either because the owner has set an ACL [ACL-EXT] which permits access by other users, or because it is a shared mailbox. This raises the issue of shared versus private annotations. If all annotations are private, it is impossible to set annotations in a shared or otherwise non-private mailbox that are visible to other users. This eliminates what could be a useful aspect of annotations in a shared environment. An example of such use is a shared IMAP folder containing bug reports. Engineers may want to use annotations to add information to existing messages, indicate assignments, status, etc. This use requires shared annotations. If all annotations are shared, it is impossible to use annotations for private notes on messages in shared mailboxes. Also, modifying an ACL to permit access to a mailbox by other users may unintentionally expose private information. There are also situations in which both shared and private annotations are useful. For example, an administrator may want to set shared annotations on messages in a shared folder, which individual users may wish to supplement with additional notes. If shared and private annotations are to coexist, we need a clear way to differentiate them. Also, it should be as easy as possible for a client to access both and not overlook either. There is also a danger in allowing a client to store an annotation without knowing if it is shared or private. This document proposes two standard suffixes for all attributes: ".shared" and ".priv". A search, fetch, or sort which specifies neither uses both. Store operations MUST explicitly use .priv or Gellens & Daboo Expires May 2002 [Page 8] Internet Draft IMAP ANNOTATE Extension November 2001 .shared suffixes. 8 IMAP Protocol Changes 8.1 ANNOTATION Message Data Item in FETCH Command This extension adds an ANNOTATION message data item to the FETCH command. This allows clients to retrieve annotations for a range of messages in the currently selected mailbox. ANNOTATION The ANNOTATION message data item, when used by the client in the FETCH command, takes an entry specifier and an attribute specifier. Example: C: a FETCH 1 (ANNOTATION ("/message/comment" "value")) S: * 1 FETCH (ANNOTATION ("/message/comment" ("value.priv" "My comment" "value.shared" "Group note"))) S: a OK Fetch complete In the above example, the content of the "value" attribute for the "/message/comment" entry is requested by the client and returned by the server. Since neither ".shared" nor ".priv" was specified, both are returned. "*" and "%" wildcard characters can be used in either specifier to match one or more characters at that position, with the exception that "%" does not match the hierarchy delimiter for the specifier it appears in (that is, "/" for an entry specifier or "." for an attribute specifier). Thus an entry specifier of "/message/%" matches entries such as "/message/comment" and "/message/subject", but not "/message/flags/redirected". Examples: C: a FETCH 1 (ANNOTATION ("/message/*" ("value.priv" "modtime.priv"))) S: * 1 FETCH (ANNOTATION (("/message/comment" ("value.priv" "My comment" "modtime.priv" "20000704000001")) ("/message/subject" ("value.priv" "Rhinoceroses!" "modtime.priv" "19991231235959")) ("/message/vendor/eudora/label.priv" ("value.priv" "label43" "modtime.priv" "20000705101502")) ("/message/vendor/eudora/personality" ("value.priv" "Tallulah Bankhead" "modtime.priv" "20000705101558")))) S: a OK Fetch complete Gellens & Daboo Expires May 2002 [Page 9] Internet Draft IMAP ANNOTATE Extension November 2001 In the above example, the contents of the private "value" and "modtime" attributes for any entries in the "/message" hierarchy are requested by the client and returned by the server. C: a FETCH 1 (ANNOTATION ("/message/%" "value.shared")) S: * 1 FETCH (ANNOTATION (("/message/comment" ("value.shared" "Patch Mangler")) ("/message/subject" ("value.shared" "Patches? We don' need no steenkin patches!")))) S: a OK Fetch complete In the above example, the contents of the shared "value" attributes for entries at the top level only of the "/message" hierarchy are requested by the client and returned by the server. Entry and attribute specifiers can be lists of atomic specifiers, so that multiple items of each type may be returned in a single FETCH command. Examples: C: a FETCH 1 (ANNOTATION (("/message/comment" "/message/subject") "value.priv")) S: * 1 FETCH (ANNOTATION (("/message/comment" ("value.priv" "What a chowder-head")) ("/message/subject" ("value.priv" "How to crush beer cans")))) S: a OK Fetch complete In the above example, the contents of the private "value" attributes for the two entries "/message/comment" and "/message/subject" are requested by the client and returned by the server. 8.2 ANNOTATION Message Data Item in FETCH Response The ANNOTATION message data item in the FETCH response displays information about annotations in a message. ANNOTATION parenthesised list The response consists of a list of entries, each of which has a list of attribute-value pairs. Examples: C: a FETCH 1 (ANNOTATION ("/message/comment" "value")) S: * 1 FETCH (ANNOTATION ("/message/comment" ("value.priv" "My comment" "value.shared" NIL))) S: a OK Fetch complete Gellens & Daboo Expires May 2002 [Page 10] Internet Draft IMAP ANNOTATE Extension November 2001 In the above example, a single entry with a single attribute-value pair is returned by the server. Since the client did not specify a ".shared" or ".priv" suffix, both are returned. Only the private attribute has a value (the shared value is NIL). C: a FETCH 1 (ANNOTATION (("/message/comment" "/message/subject") "value")) S: * 1 FETCH (ANNOTATION (("/message/comment" ("value.priv" "My comment" "value.shared" NIL)) ("/message/subject" ("value.priv" "My subject" "value.shared" NIL)))) S: a OK Fetch complete In the above example, two entries each with a single attribute-value pair are returned by the server. Since the client did not specify a ".shared" or ".priv" suffix, both are returned. Only the private attributes have values; the shared attributes are NIL. C: a FETCH 1 (ANNOTATION ("/message/comment" ("value" "modtime"))) S: * 1 FETCH (ANNOTATION (("/message/comment" ("value.priv" "My comment" "value.shared" NIL "modtime.priv" "19990203205432" "modtime.shared" NIL)))) S: a OK Fetch complete In the above example, a single entry with two attribute-value pairs is returned by the server. Since the client did not specify a ".shared" or ".priv" suffix, both are returned. Only the private attributes have values; the shared attributes are NIL. Servers SHOULD send ANNOTATION message data items in unsolicited FETCH responses if an annotation entry is changed by a third-party. This allows servers to keep clients updated with changes to annotations by other clients. Servers MUST NOT include ANNOTATION data in unsolicited responses until the client has used ANNOTATION data in a FETCH command. This restriction avoids sending ANNOTATION data to a client until the client has shown it is capable of handling it. <<>> Is this prohibition really necessary? * OK [ANNOTATIONS FLAGS MODTIME ] 8.3 ANNOTATION Message Data Item in STORE Gellens & Daboo Expires May 2002 [Page 11] Internet Draft IMAP ANNOTATE Extension November 2001 ANNOTATION Sets the specified list of entries by adding or replacing the specified attributes with the values provided. Clients can use NIL for values of attributes it wants to remove from entries. The ANNOTATION message data item used with the STORE command has an implicit ".SILENT" behavior. This means the server does not generate an untagged FETCH in response to the STORE command and assumes that the client updates its own cache if the command succeeds. Examples: C: a STORE 1 ANNOTATION ("/message/comment" ("value.priv" "My new comment")) S: a OK Store complete In the above example, the entry "/message/comment" is created (if not already present) and the private attribute "value" with data set to "My new comment" is created if not already present, or replaced if it exists. C: a STORE 1 ANNOTATION ("/message/comment" ("value.shared" NIL)) S: a OK Store complete In the above example, the shared "value" attribute of the entry "/message/comment" is removed. Multiple entries can be set in a single STORE command by listing entry-attribute-value pairs in the list. Example: C: a STORE 1 ANNOTATION ("/message/comment" ("value.priv" "Get tix Tuesday") "/message/subject" ("value.priv" "Wots On")) S: a OK Store complete In the above example, the entries "/message/comment" and "/message/subject" are created (if not already present) and the private attribute "value" is created for each entry if not already present, or replaced if they exist. Multiple attributes can be set in a single STORE command by listing multiple attribute-value pairs in the entry list. Example: C: a STORE 1 ANNOTATION ("/message/comment" ("value.priv" "My new comment" "vendor.foobar.priv" "foo's bar")) S: a OK Store complete Gellens & Daboo Expires May 2002 [Page 12] Internet Draft IMAP ANNOTATE Extension November 2001 In the above example, the entry "/message/comment" is created (if not already present) and the private attributes "value" and "vendor.foobar" are created if not already present, or replaced if they exist. 8.4 ANNOTATION Message Data Item in APPEND ANNOTATION Sets the specified list of entries and attributes in the resulting message. Example: C: a APPEND drafts ANNOTATION ("/message/comment" ("value.priv" "Don't send until we hear from Sally")) {310} S: + Ready for literal data C: MIME-Version: 1.0 ... C: S: a OK APPEND completed In the above example, a comment with a private value is added to a new message appended to the mailbox. The ellipsis represents the bulk of the message. 8.5 ANNOTATION Criterion in SEARCH The ANNOTATION criterion for the SEARCH command allows a client to search for a specified string in the value of an annotation entry of a message. ANNOTATION Messages that have annotations with entries matching and attributes matching and the specified string in their values are returned in the SEARCH results. The "*" character can be used in the entry or attribute name fields to match any content in those items. The "%" character can be used in the entry or attribute name fields to match a single level of hierarchy only. Examples: C: a SEARCH ANNOTATION "/message/comment" "value" "IMAP4" S: * SEARCH 2 3 5 7 11 13 17 19 23 S: a OK Search complete In the above example, the message numbers of any messages containing the string "IMAP4" in the shared or private "value" attribute of the "/message/comment" entry are returned in the search results. C: a SEARCH ANNOTATION "*" "*" "IMAP4" S: * SEARCH 1 2 3 5 8 13 21 34 Gellens & Daboo Expires May 2002 [Page 13] Internet Draft IMAP ANNOTATE Extension November 2001 S: a OK Search complete In the above example, the message numbers of any messages containing the string "IMAP4" in any attribute (public or private) of any entry are returned in the search results. A special case exists when the "modtime" attribute is used as the parameter in the ANNOTATION search criterion. In this case the server matches messages when the corresponding "modtime" value is greater than the value supplied in the ANNOTATION criterion. This allows a client, for example, to find out which messages contain annotations that have changed since the last time it updated its disconnected cache. Example: C: a SEARCH ANNOTATION "*" "modtime" "1999101713283412" S: * SEARCH 1 3 6 10 15 21 28 36 45 55 S: a OK Search complete In the above example, the message numbers of any messages whose "modtime" attribute of any entry exceeds the value "1999101713283412" are returned in the search results. Both public and private attributes are searched. 8.6 ANNOTATION Key in SORT The ANNOTATION criterion for the SORT command [SORT-EXT] instructs the server to return the message numbers or UIDs of a mailbox, sorted using the values of the specified annotations. The ANNOTATION criterion is available if the server returns both "ANNOTATE" and "SORT" as supported capabilities in the CAPABILITY command response. ANNOTATION Messages are sorted using the values of the attributes in the entries. (The charset argument determines sort order, as specified in the SORT extension description.) Examples: C: a SORT (ANNOTATION "/message/subject" "value.shared") UTF-8 ALL S: * SORT 2 3 4 5 1 11 10 6 7 9 8 S: a OK Sort complete In the above example, the message numbers of all messages are returned, sorted according to the shared "value" attribute of the "/message/subject" entry. Note that the ANNOTATION sort key must include a fully specified entry and attribute -- wildcards are not allowed. Gellens & Daboo Expires May 2002 [Page 14] Internet Draft IMAP ANNOTATE Extension November 2001 8.7 ACL Rights The "r" right, as specified in [ACL-EXT], is required to use annotations in any command other than STORE. The "w" right is needed to use shared annotations in the STORE command. The "s" right is needed to use private annotations in the STORE command. <<>> Should there be a special ACL bit to indicate if annotations are shared or private by default for a mailbox? 9 Interaction with MODTIME The [MODTIME-EXT] document defines an IMAP extension which allows clients to be supplied with an opaque value called a modtime. The specific value is server dependent, but has the property that all such values issued by a server are numerically increasing with respect to the order of changes. That is, for any two items, the one that was modified later has a greater modtime. 10 Formal Syntax The following syntax specification uses the Augmented Backus-Naur Form (ABNF) notation as specified in [ABNF]. Non-terminals referenced but not defined below are as defined by [IMAP4]. Except as noted otherwise, all alphabetic characters are case- insensitive. The use of upper or lower case characters to define token strings is for editorial clarity only. Implementations MUST accept these strings in a case-insensitive fashion. append = "APPEND" SP mailbox [SP flag-list] [SP date-time] [SP "ANNOTATION" SP att-annotate] SP literal ; modifies original IMAP4 APPEND command att-annotate = "(" entry-att *(SP entry-att) ")" fetch-att =/ fetch-annotate ; modifies original IMAP4 fetch-att fetch-annotate = "ANNOTATION" SP "(" entries SP attribs ")" fetch-ann-resp = "ANNOTATION" SP "(" entry-att *(SP entry-att) ")" Gellens & Daboo Expires May 2002 [Page 15] Internet Draft IMAP ANNOTATE Extension November 2001 store-att-flags =/ att-annotate ; modifies original IMAP4 STORE command search-key =/ search-annotate ; modifies original IMAP4 search-key search-annotate = "ANNOTATION" SP entry-match SP attrib-match SP value sort-key =/ sort-annotate ; modifies original ; draft-crispin-imapext-sort-xx.txt sort-key sort-annotate = "ANNOTATION" SP entry SP attrib status =/ "ANNOTATION-MODTIME" ; modifies original IMAP4 STATUS command entries = entry-match / "(" entry-match *(SP entry-match) ")" attribs = attrib-match / "(" attrib-match *(SP attrib-match) ")" entry-att = entry SP "(" att-value *(SP att-value) ") att-value = attrib SP value utf8-char = %x01-FF ; any character, excluding NUL atom-slash = any utf8-char except "/" atom-dot = any utf8-char except "." entry = DQUOTE 1*atom-slash *("/" 1*atom-slash) DQUOTE entry-match = DQUOTE 1*entry-match-atom *("/" 1*entry-match-atom) DQUOTE entry-match-atom = 1*(list-wildcards / atom-slash) *(list-wildcards / atom-slash) attrib = DQUOTE 1*atom-dot *("/" 1*atom-dot) DQUOTE attrib-match = DQUOTE 1*attrib-match-atom *("/" 1*attrib-match-atom) DQUOTE attrib-match-atom = 1*(list-wildcards / atom-dot) *(list-wildcards / atom-dot) value = nstring 11 IANA Considerations Both entry names and attribute names MUST be specified in a standards track or IESG approved experimental RFC, or fall under the vendor namespace. Vendor names MUST be registered. Gellens & Daboo Expires May 2002 [Page 16] Internet Draft IMAP ANNOTATE Extension November 2001 11.1 Entry and Attribute Registration Template To: iana@iana.org Subject: IMAP Annotate Registration Please register the following IMAP Annotate item: [] Entry [] Attribute [] Vendor [] Open: RFC _______ Name: ______________________________ Description: _______________________ ____________________________________ ____________________________________ Contact person: ____________________ email: ____________________ 12 Security Considerations Care must be taken to ensure that annotations whose values are intended to remain private are not stored in mailboxes which are accessible to other users. This includes mailboxes owned by the user by whose ACLs permit access by others as well as any shared mailboxes. 13 References [ABNF] Crocker, Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, Internet Mail Consortium, Demon Internet Ltd, November 1997. [ACAP] Newman, Myers, "ACAP -- Application Configuration Access Protocol", RFC 2244, Innosoft, Netscape, November 1997. [ACL-EXT] Myers, "IMAP4 ACL extension", RFC 2086, Carnegie Mellon, January 1997. [IMAP4] Crispin, "Internet Message Access Protocol - Version 4rev1", RFC 2060, University of Washington, December 1996. [KEYWORDS] Bradner, "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, Harvard University, March 1997. [MODTIME-EXT] Melnikov, "IMAP Conditional Store", work in progress. Gellens & Daboo Expires May 2002 [Page 17] Internet Draft IMAP ANNOTATE Extension November 2001 [SMTP-DSN] Moore, "SMTP Service Extension for Delivery Status Notifications", RFC 1891, University of Tennessee, January 1996. [SORT-EXT] Crispin, "Internet Message Access Protocol -- SORT Extension", work in progress. 14 Acknowledgments Many thanks to Chris Newman for his detailed comments on the first draft of this document, and to the participants at the ACAP working dinner in Pittsburgh. 15 Authors' Addresses Randall Gellens QUALCOMM Incorporated 5775 Morehouse Dr. San Diego, CA 92121-2779 U.S.A. Email: randy@qualcomm.com Cyrus Daboo Cyrusoft International, Inc. Suite 780, 5001 Baum Blvd. Pittsburgh, PA 15213 U.S.A. Email: daboo@cyrusoft.com 16 Full Copyright Statement Copyright (C) The Internet Society 2001. All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. Gellens & Daboo Expires May 2002 [Page 18] Internet Draft IMAP ANNOTATE Extension November 2001 The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Gellens & Daboo Expires May 2002 [Page 19]