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diff --git a/doc/rfc/rfc5257.txt b/doc/rfc/rfc5257.txt new file mode 100644 index 0000000..1d088e5 --- /dev/null +++ b/doc/rfc/rfc5257.txt @@ -0,0 +1,1739 @@ + + + + + + +Network Working Group C. Daboo +Request for Comments: 5257 Apple Inc. +Category: Experimental R. Gellens + QUALCOMM Incorporated + June 2008 + + + Internet Message Access Protocol - ANNOTATE Extension + +Status of This Memo + + This memo defines an Experimental Protocol for the Internet + community. It does not specify an Internet standard of any kind. + Discussion and suggestions for improvement are requested. + Distribution of this memo is unlimited. + +Abstract + + The ANNOTATE extension to the Internet Message Access Protocol + permits clients and servers to maintain "meta data" for messages, or + individual message parts, stored in a mailbox on the server. For + example, this can be used to attach comments and other useful + information to a message. It is also possible to attach annotations + to specific parts of a message, so that, for example, they could be + marked as seen, or important, or a comment added. + + Note that this document was the product of a WG that had good + consensus on how to approach the problem. Nevertheless, the WG felt + it did not have enough information on implementation and deployment + hurdles to meet all of the requirements of a Proposed Standard. The + IETF solicits implementations and implementation reports in order to + make further progress. + + Implementers should be aware that this specification may change in an + incompatible manner when going to Proposed Standard status. However, + any incompatible changes will result in a new capability name being + used to prevent problems with any deployments of the experimental + extension. + + + + + + + + + + + + + +Daboo & Gellens Experimental [Page 1] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + +Table of Contents + + 1. Introduction and Overview .......................................3 + 2. Conventions Used in This Document ...............................4 + 3. Data Model ......................................................4 + 3.1. Overview ...................................................4 + 3.2. Namespace of Entries and Attributes ........................4 + 3.2.1. Entry Names .........................................5 + 3.2.2. Attribute Names .....................................7 + 3.3. Private Versus Shared ......................................7 + 3.4. Access Control .............................................8 + 3.5. Access to Standard IMAP Flags and Keywords ................11 + 4. IMAP Protocol Changes ..........................................11 + 4.1. General Considerations ....................................11 + 4.2. ANNOTATE Parameter with the SELECT/EXAMINE Commands .......12 + 4.3. ANNOTATION Message Data Item in FETCH Command .............12 + 4.4. ANNOTATION Message Data Item in FETCH Response ............14 + 4.5. ANNOTATION Message Data Item in STORE .....................16 + 4.6. ANNOTATION Interaction with COPY ..........................18 + 4.7. ANNOTATION Message Data Item in APPEND ....................18 + 4.8. ANNOTATION Criterion in SEARCH ............................19 + 4.9. ANNOTATION Key in SORT ....................................20 + 4.10. New ACL Rights ...........................................21 + 5. Formal Syntax ..................................................21 + 6. IANA Considerations ............................................23 + 6.1. Entry and Attribute Registration Template .................23 + 6.2. Entry Registrations .......................................24 + 6.2.1. /comment ...........................................24 + 6.2.2. /flags .............................................24 + 6.2.3. /altsubject ........................................25 + 6.2.4. /<section-part>/comment ............................25 + 6.2.5. /<section-part>/flags/seen .........................26 + 6.2.6. /<section-part>/flags/answered .....................26 + 6.2.7. /<section-part>/flags/flagged ......................27 + 6.2.8. /<section-part>/flags/forwarded ....................27 + 6.3. Attribute Registrations ...................................28 + 6.3.1. value ..............................................28 + 6.3.2. size ...............................................28 + 6.4. Capability Registration ...................................28 + 7. Internationalization Considerations ............................29 + 8. Security Considerations ........................................29 + 9. References .....................................................29 + 9.1. Normative References ......................................29 + 9.2. Informative References ....................................30 + 10. Acknowledgments ...............................................30 + + + + + + +Daboo & Gellens Experimental [Page 2] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + +1. Introduction and Overview + + The ANNOTATE extension is present in any IMAP [RFC3501] + implementation that returns "ANNOTATE-EXPERIMENT-1" as one of the + supported capabilities in the CAPABILITY response. + + This extension makes the following changes to the IMAP 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 the SORT extension. + + e. adds a new ANNOTATION data item for use in APPEND. + + f. adds a new requirement on the COPY command. + + g. adds a new ANNOTATE parameter for use with the SELECT/EXAMINE + commands. + + h. adds two new response codes to indicate store failures of + annotations. + + i. adds a new untagged response code for the SELECT or EXAMINE + commands to indicate the maximum sized annotation that can be + stored. + + j. adds a new Access Control List (ACL) "bit" for use with the ACL + extensions [RFC2086] and [RFC4314]. + + The data model used for the storage of annotations is based on the + Application Configuration Access Protocol [RFC2244]. Note that there + is no inheritance in annotations. + + If a server supports annotations, then it MUST store all annotation + data permanently, i.e., there is no concept of "session only" + annotations that would correspond to the behavior of "session" flags + as defined in the IMAP base specification. + + In order to provide optimum support for a disconnected client (one + that needs to synchronize annotations for use when offline), servers + SHOULD also support the Conditional STORE [RFC4551] extension. + + The rest of this document describes the data model and protocol + changes more rigorously. + + + +Daboo & Gellens Experimental [Page 3] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + +2. Conventions Used in This Document + + The examples in this document use "C:" and "S:" to indicate lines + sent by the client and server, respectively. + + 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 [RFC2119]. + +3. Data Model + +3.1. Overview + + The data model for annotations in ANNOTATE uses a uniquely named + entry that contains a set of standard attributes. Thus, a single + coherent unit of "meta data" for a message is stored as a single + entry, made up of several attributes. + + For example, a comment annotation added to a message has an entry + name of "/comment". This entry is composed of several attributes + such as "value", "size", etc., that 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 attribute in any entry in a + message annotation, assuming it has sufficient access rights to do so + (see Section 3.4 for specifics). + +3.2. Namespace of Entries and Attributes + + A message may contain zero or more annotations, each of which is a + single uniquely named entry. Each entry has a hierarchical name, + with each component of the name separated by a slash ("/"). An entry + name MUST NOT contain two consecutive "/" characters and MUST NOT end + with a "/" character. + + Each entry is made up of a set of attributes. Each attribute has a + hierarchical name, with each component of the name separated by a + period ("."). An attribute name MUST NOT contain two consecutive "." + characters and MUST NOT end with a "." character. + + 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 NOT contain non-ASCII characters or the + NULL octet. Invalid entry or attribute names result in a BAD + response in any IMAP commands where they are used. + + + +Daboo & Gellens Experimental [Page 4] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + Attribute names MUST NOT contain any hierarchical components with the + names "priv" or "shared", as those have special meaning (see Section + 3.3). + + Entry and attribute names are case-sensitive. + + Use of control or punctuation 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 as needed. + +3.2.1. Entry Names + + Entry names MUST be specified in a standards track or IESG approved + experimental RFC, or fall under the vendor namespace. See Section + 6.1 for the registration template. + + / + Defines the top-level of entries associated with an entire + message. This entry itself does not contain any attributes. All + entries that start with a numeric character ("0" - "9") refer to + an annotation on a specific body part. All other entries are for + annotations on the entire message. + + /comment + Defines a comment or note associated with an entire message. + + /flags + This entry hierarchy is reserved for future use. + + /altsubject + Contains text supplied by the message recipient to be used by the + client, instead of the original message Subject. + + /vendor/<vendor-token> + 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 + annotations. The vendor-token MUST be registered with IANA, using + the [RFC2244] vendor subtree registry. + + /<section-part> + Defines the top-level of entries associated with a specific body + part of a message. This entry itself does not contain any + attributes. The section-part is a numeric part specifier. Its + + + +Daboo & Gellens Experimental [Page 5] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + syntax is the same as the section-part ABNF element defined in + [RFC3501]. The server MUST return a BAD response if the client + uses an incorrect part specifier (either incorrect syntax or a + specifier referring to a non-existent part). The server MUST + return a BAD response if the client uses an empty part specifier + (which is used in IMAP to represent the entire message). + + /<section-part>/comment + Defines a comment or note associated with a specific body part of + a message. + + /<section-part>/flags + Defines the top-level of entries associated with the 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. + + /<section-part>/flags/seen + This is similar to the IMAP \Seen flag, except it applies + to only the body part referenced by the entry. + + /<section-part>/flags/answered + This is similar to the IMAP \Answered flag, except it + applies to only the body part referenced by the entry. + + /<section-part>/flags/flagged + This is similar to the IMAP \Flagged flag, except it + applies to only the body part referenced by the entry. + + /<section-part>/flags/forwarded + This is similar to the IMAP $Forwarded keyword, except it + applies to only the body part referenced by the entry. + + Defines flags for a specific body part of a message. The "value" + attribute of each of the entries described above must be either + "1", "0", or "NIL". "1" corresponds to the flag being set. + + /<section-part>/vendor/<vendor-token> + 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 annotations. The vendor-token MUST be registered with + IANA. + + + + + + + + +Daboo & Gellens Experimental [Page 6] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + +3.2.2. Attribute Names + + Attribute names MUST be specified in a standards track or IESG + approved experimental RFC. See Section 6.1 for the registration + template. + + All attribute names implicitly have a ".priv" and a ".shared" suffix + that maps to private and shared versions of the entry. Searching or + fetching without using either suffix will include both. The client + MUST specify either a ".priv" or ".shared" suffix when storing an + annotation or sorting on annotations. + + value + A string or binary data representing the value of the annotation. + To delete an annotation, the client can store "NIL" into the + value. If the client requests the value attribute for a non- + existent entry, then the server MUST return "NIL" for the value. + The content represented by the string is determined by the + content-type used to register the entry (see Section 6.1 for entry + registration templates). Where applicable, the registered + content-type MUST include a charset parameter. Text values SHOULD + use the utf-8 [RFC3629] character set. Note that binary data + (data which may contain the NULL octet) is allowed (e.g., for + storing images), and this extension uses the "literal8" syntax + element [RFC4466] to allow such data to be written to or read from + the server. + + size + The size of the value, in octets. Set automatically by the + server, read-only to clients. If the client requests the size + attribute for a non-existent entry, then the server MUST return + "0" (zero) for the size. + +3.3. 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 + [RFC4314] that 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 then impossible to have + annotations in a shared or otherwise non-private mailbox be 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 + + + + +Daboo & Gellens Experimental [Page 7] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + 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 or FETCH command that specifies + neither, uses both. STORE, APPEND, and SORT commands MUST explicitly + use ".priv" or ".shared" suffixes. + + If the ANNOTATE extension is present, support for shared annotations + in servers is REQUIRED, while support for private annotations in + servers is OPTIONAL. This recognizes the fact that support for + private annotations may introduce a significant increase in + complexity to a server in terms of tracking ownership of the + annotations, how quota is determined for users based on their own + annotations, etc. Clients that support the ANNOTATE extension MUST + handle both shared and private annotations. + +3.4. Access Control + + A user needs to have appropriate rights in order to read or write + ".priv" or ".shared" annotation values. How those rights are + calculated depends on whether or not the ACL [RFC2086] extension or + its update [RFC4314] is present. If a client attempts to store or + fetch an annotation to which they do not have the appropriate rights, + the server MUST respond with a NO response. + + When the ACL extension is not present, access to annotation values is + governed by the nature of the selected state, in particular whether + the mailbox was SELECTED or EXAMINED in READ-ONLY or READ-WRITE mode. + + + + + + +Daboo & Gellens Experimental [Page 8] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + When the ACL extension is present, the server MUST recognize the new + ACL "n" right, in addition to the ones defined by the ACL extension + itself. + + For ".priv" annotation values, the "r" right controls both read and + write access. When it is on, access to ".priv" annotations is + allowed; when it is off, access to ".priv" annotations is disallowed. + + For ".shared" annotation values, the "r" right controls read access. + When it is on, ".shared" annotations can be read; when it is off, + ".shared" annotations cannot be read. + + For ".shared" annotation values, the "n" right controls write access. + When it is on, ".shared" annotations can be changed or created + through either a STORE or APPEND command; when it is off, ".shared" + annotations cannot be changed or created. The "n" right constitutes + a "shared flag right" as defined in Section 6.2 of [RFC4314]. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Daboo & Gellens Experimental [Page 9] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + A summary of all the access control restrictions is tabulated below + + +---------------+---------------+-----------------------------------+ + | Server Type | Action on | Type of mailbox | + | | annotation | | + +===============+===============+===================================+ + | | | | + | | read .priv | Any mailbox that can be SELECTED | + | | values | or EXAMINED. | + | | | | + | +---------------+-----------------------------------+ + | | | | + | | write .priv | Any SELECTED [READ-WRITE] mailbox.| + | | values | SELECTED [READ-ONLY] mailboxes MAY| + | Server | | also permit writes. | + | without | | | + | ACL Extension +---------------+-----------------------------------+ + | | | | + | | read .shared | Any mailbox that can be SELECTED | + | | values | or EXAMINED. | + | | | | + | +---------------+-----------------------------------+ + | | | | + | | write .shared | Any mailbox that can be SELECTED | + | | values | or EXAMINED and is [READ-WRITE]. | + | | | | + +---------------+---------------+-----------------------------------+ + | | | | + | | read .priv | Any mailbox with the "r" | + | | values | ACL right. | + | | | | + | +---------------+-----------------------------------+ + | | | | + | | write .priv | Any mailbox with the "r" | + | Server | values | ACL right. | + | with | | | + | ACL Extension +---------------+-----------------------------------+ + | | | | + | | read .shared | Any mailbox with the "r" | + | | values | ACL right. | + | | | | + | +---------------+-----------------------------------+ + | | | | + | | write .shared | Any mailbox with the "n" | + | | values | ACL right. | + | | | | + +---------------+---------------+-----------------------------------+ + + + + +Daboo & Gellens Experimental [Page 10] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + +3.5. Access to Standard IMAP Flags and Keywords + + Due to the ambiguity of how private and shared values would map to + the base IMAP flag and keyword values, the ANNOTATE extension does + not expose IMAP flags or keywords as entries. However, the /flags + annotation entry is reserved for future use and MUST NOT be used by + clients or servers supporting this extension. + + Clients that need to implement shared and private "flags" can create + their own annotation entries for those, completely bypassing the base + IMAP flag/keyword behavior. + +4. IMAP Protocol Changes + +4.1. General Considerations + + Servers may be able to offer only a limited level of support for + annotations in mailboxes, and it is useful for clients to be able to + know what level of support is available. Servers MUST return an + ANNOTATIONS response code during the SELECT or EXAMINE command for a + mailbox to indicate the level of support. Possible data items used + with the ANNOTATIONS response code are: + + "NONE" - this indicates that the mailbox being selected does not + support annotations at all. Clients MUST NOT attempt to use + annotation extensions in commands for this mailbox. + + "READ-ONLY" - this indicates that the annotations supported by the + mailbox cannot be changed by the client. Clients MUST NOT attempt + to store annotations on any messages in a mailbox with this + response code. + + "NOPRIVATE" - this indicates that the server does not support + private annotations on the mailbox. Only shared annotations are + supported. Clients SHOULD only attempt to read or store + annotations attributes with the ".shared" suffix. If a client + uses an attribute with the ".priv" suffix in a FETCH command, then + servers should return the attribute value in the FETCH response as + "NIL". If a client uses an attribute with the ".priv" suffix in a + STORE command (or an APPEND command targeted at the mailbox), then + the server MUST return a NO response. + + numeric values - if servers support writable annotations, then the + server MUST indicate the maximum size in octets for an annotation + value by providing the maximum size value in the response code. + Clients MUST NOT store annotation values of a size greater than + the amount indicated by the server. Servers MUST accept a minimum + + + + +Daboo & Gellens Experimental [Page 11] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + annotation data size of at least 1024 octets if annotations can be + written. + + In addition, the server MAY limit the total number of annotations for + a single message. However, the server MUST provide a minimum + annotation count per message of at least 10. + +4.2. ANNOTATE Parameter with the SELECT/EXAMINE Commands + + The ANNOTATE extension defines a single optional SELECT parameter + [RFC4466] "ANNOTATE", which is used to turn on unsolicited responses + for annotations as described in Section 4.4. This optional parameter + results in a per-mailbox state change, i.e., it must be used in each + SELECT/EXAMINE command in order to be effective, irrespective of + whether it was used in a previous SELECT/EXAMINE during the same + session. + + Example: + + C: a SELECT INBOX (ANNOTATE) + S: * FLAGS (\Answered \Flagged \Draft \Deleted \Seen) + S: * OK [PERMANENTFLAGS (\Answered \Flagged \Draft + \Deleted \Seen \*)] + S: * 10268 EXISTS + S: * 1 RECENT + S: * OK [UNSEEN 10268] + S: * OK [UIDVALIDITY 890061587] + S: * OK [UIDNEXT 34643] + S: * OK [ANNOTATIONS 20480 NOPRIVATE] + S: a OK [READ-WRITE] Completed + + In the above example, a SELECT command with the ANNOTATE parameter + is issued. The response from the server includes the required + ANNOTATIONS response that indicates that the server supports + annotations up to a maximum size of 20480 octets, and does not + support private annotations (only shared). + +4.3. 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 <entry-specifier> <attribute-specifier> + + The ANNOTATION message data item, when used by the client in the + FETCH command, takes an entry specifier and an attribute + specifier. + + + +Daboo & Gellens Experimental [Page 12] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + Example: + + C: a FETCH 1 (ANNOTATION (/comment value)) + S: * 1 FETCH (ANNOTATION (/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 + "/comment" entry is requested by the client and returned by the + server. Since neither ".shared" nor ".priv" was specified, both + are returned. + + "*" and "%" wild card characters can be used in entry specifiers to + match one or more characters at that position, with the exception + that "%" does not match the "/" hierarchy delimiter. Thus, an entry + specifier of "/%" matches entries such as "/comment" and + "/altsubject", but not "/1/comment". + + Example: + + C: a UID FETCH 1123 (UID ANNOTATION + (/* (value.priv size.priv))) + S: * 12 FETCH (UID 1123 ANNOTATION + (/comment (value.priv "My comment" + size.priv "10") + /altsubject (value.priv "Rhinoceroses!" + size.priv "13") + /vendor/foobar/label.priv + (value.priv "label43" + size.priv "7") + /vendor/foobar/personality + (value.priv "Tallulah Bankhead" + size.priv "17"))) + S: a OK Fetch complete + + In the above example, the contents of the private "value" and + "size" attributes for any entries in the "/" hierarchy are + requested by the client and returned by the server. + + + + + + + + + + + + +Daboo & Gellens Experimental [Page 13] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + Example: + + C: a FETCH 1 (ANNOTATION (/% value.shared)) + S: * 1 FETCH (ANNOTATION + (/comment (value.shared "Patch Mangler") + /altsubject (value.shared "Patches? We don't + 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 "/" 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. + + Example: + + C: a FETCH 1 (ANNOTATION + ((/comment /altsubject) value.priv)) + S: * 1 FETCH (ANNOTATION + (/comment (value.priv "What a chowder-head") + /altsubject (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 "/comment" and "/altsubject" are + requested by the client and returned by the server. + +4.4. ANNOTATION Message Data Item in FETCH Response + + The ANNOTATION message data item in the FETCH response displays + information about annotations in a message. + + ANNOTATION parenthesized list + + The response consists of a list of entries, each of which have a + list of attribute-value pairs. + + + + + + + + + + + + +Daboo & Gellens Experimental [Page 14] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + Example: + + C: a FETCH 1 (ANNOTATION (/comment value)) + S: * 1 FETCH (ANNOTATION (/comment + (value.priv "My comment" + value.shared NIL))) + S: a OK Fetch complete + + 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"). + + Example: + + C: a FETCH 1 (ANNOTATION + ((/comment /altsubject) value)) + S: * 1 FETCH (ANNOTATION + (/comment (value.priv "My comment" + value.shared NIL) + /altsubject (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". + + Example: + + C: a FETCH 1 (ANNOTATION + (/comment (value size))) + S: * 1 FETCH (ANNOTATION + (/comment + (value.priv "My comment" + value.shared NIL + size.priv "10" + size.shared "0"))) + 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". + + + + + +Daboo & Gellens Experimental [Page 15] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + Servers SHOULD send ANNOTATION message data items in unsolicited + FETCH responses if an annotation entry is changed by a third-party, + and the ANNOTATE select parameter was used. This allows servers to + keep clients updated with changes to annotations by other clients. + + Unsolicited ANNOTATION responses MUST NOT include ANNOTATION data + values -- only the entry name of the ANNOTATION that has changed. + This restriction avoids sending ANNOTATION data values (which may be + large) to a client unless the client explicitly asks for the value. + + Example: + + C: a STORE 1 +FLAGS (\Seen) + S: * 1 FETCH (FLAGS (\Seen)) + ANNOTATION (/comment)) + S: a OK STORE complete + + In the above example, an unsolicited ANNOTATION response is + returned during a STORE command. The unsolicited response + contains only the entry name of the annotation that changed, and + not its value. + +4.5. ANNOTATION Message Data Item in STORE + + ANNOTATION <parenthesized entry-attribute-value list> + + 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. Though + note, that if the Conditional STORE extension [RFC4551] is present, + then an untagged FETCH response with a MODSEQ data item will be + returned by the server as required by [RFC4551]. + + If the server is unable to store an annotation because the size of + its value is too large, the server MUST return a tagged NO response + with a "[ANNOTATE TOOBIG]" response code. + + If the server is unable to store a new annotation because the maximum + number of allowed annotations has already been reached, the server + MUST return a tagged NO response with a "[ANNOTATE TOOMANY]" response + code. + + + + + +Daboo & Gellens Experimental [Page 16] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + Example: + + C: a STORE 1 ANNOTATION (/comment + (value.priv "My new comment")) + S: a OK Store complete + + In the above example, the entry "/comment" is created (if not + already present). Its private attribute "value" is created if not + already present, or replaced if it exists. "value.priv" is set to + "My new comment". + + Example: + + C: a STORE 1 ANNOTATION (/comment + (value.shared NIL)) + S: a OK Store complete + + In the above example, the shared "value" attribute of the entry + "/comment" is removed by storing "NIL" into the attribute. + + 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 (/comment + (value.priv "Get tix Tuesday") + /altsubject + (value.priv "Wots On")) + S: a OK Store complete + + In the above example, the entries "/comment" and "/altsubject" are + created (if not already present) and the private attribute "value" + is created or replaced for each entry. + + Multiple attributes can be set in a single STORE command by listing + multiple attribute-value pairs in the entry list. + + + + + + + + + + + + + + +Daboo & Gellens Experimental [Page 17] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + Example: + + C: a STORE 1 ANNOTATION (/comment + (value.priv "My new comment" + value.shared "foo's bar")) + S: a OK Store complete + + In the above example, the entry "/comment" is created (if not + already present) and the private and shared "value" attributes are + created if not already present, or replaced if they exist. + +4.6. ANNOTATION Interaction with COPY + + The COPY command can be used to move messages from one mailbox to + another on the same server. Servers that support the ANNOTATION + extension MUST, for each message being copied, copy all ".priv" + annotation data for the current user only, and all ".shared" + annotation data along with the message to the new mailbox. The only + exceptions to this are if the destination mailbox permissions are + such that either the ".priv" or ".shared" annotations are not + allowed, or if the destination mailbox is of a type that does not + support annotations or does not support storing of annotations (a + mailbox that returns a "NONE" or "READ-ONLY" response code in its + ANNOTATIONS response), or if the destination mailbox cannot support + the size of an annotation because it exceeds the ANNOTATIONS value. + Servers MUST NOT copy ".priv" annotation data for users other than + the current user. + +4.7. ANNOTATION Message Data Item in APPEND + + ANNOTATION <parenthesized entry-attribute-value list> + + Sets the specified list of entries and attributes in the resulting + message. + + The APPEND command can include annotations for the message being + appended via the addition of a new append data item [RFC4466]. The + new data item can also be used with the multi-append [RFC3502] + extension that allows multiple messages to be appended via a single + APPEND command. + + + + + + + + + + + +Daboo & Gellens Experimental [Page 18] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + Example: + + C: a APPEND drafts ANNOTATION (/comment + (value.priv "Don't send until I say so")) {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. + +4.8. ANNOTATION Criterion in SEARCH + + ANNOTATION <entry-name> <attribute-name> <value> + + 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. + + Messages that have annotations with entries matching <entry-name>, + attributes matching <attribute-name>, and the specified string + <value> in their values are returned in the SEARCH results. The "*" + character can be used in the entry name field to match any content in + those items. The "%" character can be used in the entry name field + to match a single level of hierarchy only. + + Only the "value", "value.priv", and "value.shared" attributes can be + searched. Clients MUST NOT specify an attribute other than either + "value", "value.priv", or "value.shared". Servers MUST return a BAD + response if the client tries to search any other attribute. + + Example: + + C: a SEARCH ANNOTATION /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 "/comment" entry are returned in the search + results. + + + + + + + +Daboo & Gellens Experimental [Page 19] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + Example: + + C: a SEARCH ANNOTATION * value.priv "IMAP4" + S: * SEARCH 1 2 3 5 8 13 21 34 + S: a OK Search complete + + In the above example, the message numbers of any messages + containing the string "IMAP4" in the private "value" attribute of + any entry are returned in the search results. + +4.9. ANNOTATION Key in SORT + + ANNOTATION <entry-name> <attribute-name> + + The ANNOTATION criterion for the SORT command [RFC5256] instructs the + server to return the sequence numbers or Unique Identifiers (UIDs) of + messages in a mailbox, sorted using the values of the specified + annotations. The ANNOTATION criterion is available if the server + returns both ANNOTATE-EXPERIMENT-1 and SORT as supported capabilities + in the CAPABILITY command response. + + Messages are sorted using the values of the <attribute-name> + attributes in the <entry-name> entries. + + Clients MUST provide either the ".priv" or ".shared" suffix to the + attribute name to ensure that the server knows which specific value + to sort on. + + Only the "value.priv" and "value.shared" attributes can be used for + sorting. Clients MUST NOT specify an attribute other than either + "value.priv" or "value.shared". Servers MUST return a BAD response + if the client tries to sort on any other attribute. + + When either "value.priv" or "value.shared" is being sorted, the + server MUST use the character set value specified in the SORT command + to determine the appropriate sort order. + + Example: + + C: a SORT (ANNOTATION /altsubject 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 + "/altsubject" entry. + + + + + +Daboo & Gellens Experimental [Page 20] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + Note that the ANNOTATION sort key must include a fully specified + entry -- wild cards are not allowed. + +4.10. New ACL Rights + + As discussed in Section 3.4, this extension adds a new "n" right to + the list of rights provided by the ACL extensions [RFC2086] and + [RFC4314]. + +5. Formal Syntax + + The following syntax specification uses the Augmented Backus-Naur + Form (ABNF) notation as specified in [RFC5234]. + + Non-terminals referenced but not defined below are as defined by + [RFC3501] with the new definitions in [RFC4466] superseding those in + [RFC3501]. + + 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. + + ann-size = "NONE" / + (("READ-ONLY" / nz-number) + [SP "NOPRIVATE"]) + ; response codes indicating the level of + ; support for annotations in a mailbox + + append-ext =/ att-annotate + ; modifies [RFC3501] extension behaviour + + att-annotate = "ANNOTATION" SP + "(" entry-att *(SP entry-att) ")" + + att-search = "value" / "value.priv" / "value.shared" + ; the only attributes that can be searched + + att-sort = "value.priv" / "value.shared" + ; the only attributes that can be sorted + + att-value = attrib SP value + + attrib = astring + ; dot-separated attribute name + ; MUST NOT contain "*" or "%" + + + + + +Daboo & Gellens Experimental [Page 21] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + attribs = attrib / "(" attrib *(SP attrib) ")" + ; one or more attribute specifiers + + capability =/ "ANNOTATE-EXPERIMENT-1" + ; defines the capability for this extension + + entries = entry-match / + "(" entry-match *(SP entry-match) ")" + + entry = astring + ; slash-separated path to entry + ; MUST NOT contain "*" or "%" + + entry-att = entry SP "(" att-value *(SP att-value) ")" + + entry-match = list-mailbox + ; slash-separated path to entry + ; MAY contain "*" or "%" for use as wild cards + + fetch-att =/ "ANNOTATION" SP "(" entries SP attribs ")" + ; modifies original IMAP fetch-att + + msg-att-dynamic =/ "ANNOTATION" SP + ( "(" entry-att *(SP entry-att) ")" / + "(" entry *(SP entry) ")" ) + ; extends FETCH response with annotation data + + resp-text-code =/ "ANNOTATE" SP "TOOBIG" / + "ANNOTATE" SP "TOOMANY" / + "ANNOTATIONS" SP ann-size + ; new response codes + + search-key =/ "ANNOTATION" SP entry-match SP att-search + SP value + ; modifies original IMAP search-key + + select-param =/ "ANNOTATE" + ; defines the select parameter used with + ; ANNOTATE extension + + sort-key =/ "ANNOTATION" SP entry SP att-sort + ; modifies original sort-key + + store-att-flags =/ att-annotate + ; modifies original IMAP STORE command + + value = nstring / literal8 + + + + +Daboo & Gellens Experimental [Page 22] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + +6. IANA Considerations + + Entry names MUST be specified in a standards track or IESG approved + experimental RFC, or fall under the vendor namespace. Vendor names + MUST be registered. + + Attribute names MUST be specified in a standards track or IESG + approved experimental RFC. + + Each entry registration MUST include a content-type that is used to + indicate the nature of the annotation value. Where applicable, a + charset parameter MUST be included with the content-type. + +6.1. Entry and Attribute Registration Template + + To: iana@iana.org + Subject: IMAP Annotate Registration + + Please register the following IMAP Annotate item: + + [] Entry [] Attribute + + Name: ______________________________ + + Description: _______________________ + + ____________________________________ + + ____________________________________ + + Content-Type:_______________________ + + Contact person: ____________________ + + email: ____________________ + + + + + + + + + + + + + + + + +Daboo & Gellens Experimental [Page 23] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + +6.2. Entry Registrations + + The following templates specify the IANA registrations of annotation + entries specified in this document. + +6.2.1. /comment + + To: iana@iana.org + Subject: IMAP Annotate Registration + + Please register the following IMAP Annotate item: + + [X] Entry [] Attribute + + Name: /comment + + Description: Defined in IMAP ANNOTATE extension document. + + Content-Type: text/plain; charset=utf-8 + + Contact person: Cyrus Daboo + + email: cyrus@daboo.name + +6.2.2. /flags + + To: iana@iana.org + Subject: IMAP Annotate Registration + + Please register the following IMAP Annotate item: + + [X] Entry [] Attribute + + Name: /flags + + Description: Reserved entry hierarchy. + + Content-Type: - + + Contact person: Cyrus Daboo + + email: cyrus@daboo.name + + + + + + + + + +Daboo & Gellens Experimental [Page 24] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + +6.2.3. /altsubject + + To: iana@iana.org + Subject: IMAP Annotate Registration + + Please register the following IMAP Annotate item: + + [X] Entry [] Attribute + + Name: /altsubject + + Description: Defined in IMAP ANNOTATE extension document. + + Content-Type: text/plain; charset=utf-8 + + Contact person: Cyrus Daboo + + email: cyrus@daboo.name + +6.2.4. /<section-part>/comment + + To: iana@iana.org + Subject: IMAP Annotate Registration + + Please register the following IMAP Annotate item: + + [X] Entry [] Attribute + + Name: /<section-part>/comment + + Description: Defined in IMAP ANNOTATE extension document. + + Content-Type: text/plain; charset=utf-8 + + Contact person: Cyrus Daboo + + email: cyrus@daboo.name + + + + + + + + + + + + + + +Daboo & Gellens Experimental [Page 25] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + +6.2.5. /<section-part>/flags/seen + + To: iana@iana.org + Subject: IMAP Annotate Registration + + Please register the following IMAP Annotate item: + + [X] Entry [] Attribute + + Name: /<section-part>/flags/seen + + Description: Defined in IMAP ANNOTATE extension document. + + Content-Type: text/plain; charset=utf-8 + + Contact person: Cyrus Daboo + + email: cyrus@daboo.name + +6.2.6. /<section-part>/flags/answered + + To: iana@iana.org + Subject: IMAP Annotate Registration + + Please register the following IMAP Annotate item: + + [X] Entry [] Attribute + + Name: /<section-part>/flags/answered + + Description: Defined in IMAP ANNOTATE extension document. + + Content-Type: text/plain; charset=utf-8 + + Contact person: Cyrus Daboo + + email: cyrus@daboo.name + + + + + + + + + + + + + + +Daboo & Gellens Experimental [Page 26] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + +6.2.7. /<section-part>/flags/flagged + + To: iana@iana.org + Subject: IMAP Annotate Registration + + Please register the following IMAP Annotate item: + + [X] Entry [] Attribute + + Name: /<section-part>/flags/flagged + + Description: Defined in IMAP ANNOTATE extension document. + + Content-Type: text/plain; charset=utf-8 + + Contact person: Cyrus Daboo + + email: cyrus@daboo.name + +6.2.8. /<section-part>/flags/forwarded + + To: iana@iana.org + Subject: IMAP Annotate Registration + + Please register the following IMAP Annotate item: + + [X] Entry [] Attribute + + Name: /<section-part>/flags/forwarded + + Description: Defined in IMAP ANNOTATE extension document. + + Content-Type: text/plain; charset=utf-8 + + Contact person: Cyrus Daboo + + email: cyrus@daboo.name + + + + + + + + + + + + + + +Daboo & Gellens Experimental [Page 27] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + +6.3. Attribute Registrations + + The following templates specify the IANA registrations of annotation + attributes specified in this document. + +6.3.1. value + + To: iana@iana.org + Subject: IMAP Annotate Registration + + Please register the following IMAP Annotate item: + + [] Entry [X] Attribute + + Name: value + + Description: Defined in IMAP ANNOTATE extension document. + + Contact person: Cyrus Daboo + + email: cyrus@daboo.name + +6.3.2. size + + To: iana@iana.org + Subject: IMAP Annotate Registration + + Please register the following IMAP Annotate item: + + [] Entry [X] Attribute + + Name: size + + Description: Defined in IMAP ANNOTATE extension document. + + Contact person: Cyrus Daboo + + email: cyrus@daboo.name + +6.4. Capability Registration + + This document registers "ANNOTATE-EXPERIMENT-1" as an IMAPEXT + capability. + + + + + + + + +Daboo & Gellens Experimental [Page 28] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + +7. Internationalization Considerations + + Annotations may contain values that include text strings, and both + searching and sorting are possible with annotations. Servers MUST + follow standard IMAP text normalization, character set conversion, + and collation rules when such operations are carried out, as would be + done for other textual fields being searched or sorted on. + +8. Security Considerations + + Annotations whose values are intended to remain private MUST be + stored in ".priv" values instead of ".shared" values, which may be + accessible to other users. + + Excluding the above issues, the ANNOTATE extension does not raise any + security considerations that are not present in the base IMAP + protocol; these issues are discussed in [RFC3501]. + +9. References + +9.1. Normative References + + [RFC2086] Myers, J., "IMAP4 ACL extension", RFC 2086, January 1997. + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [RFC2244] Newman, C. and J. Myers, "ACAP -- Application + Configuration Access Protocol", RFC 2244, November 1997. + + [RFC3501] Crispin, M., "INTERNET MESSAGE ACCESS PROTOCOL - VERSION + 4rev1", RFC 3501, March 2003. + + [RFC3502] Crispin, M., "Internet Message Access Protocol (IMAP) - + MULTIAPPEND Extension", RFC 3502, March 2003. + + [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO + 10646", STD 63, RFC 3629, November 2003. + + [RFC4314] Melnikov, A., "IMAP4 Access Control List (ACL) Extension", + RFC 4314, December 2005. + + [RFC4466] Melnikov, A. and C. Daboo, "Collected Extensions to IMAP4 + ABNF", RFC 4466, April 2006. + + [RFC5234] Crocker, D., Ed., and P. Overell, "Augmented BNF for + Syntax Specifications: ABNF", STD 68, RFC 5234, January + 2008. + + + +Daboo & Gellens Experimental [Page 29] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + + [RFC5256] Crispin, M. and K. Murchison, "Internet Message Access + Protocol - SORT and THREAD Extensions", RFC 5256, June + 2008. + +9.2. Informative References + + [RFC4551] Melnikov, A. and S. Hole, "IMAP Extension for Conditional + STORE Operation or Quick Flag Changes Resynchronization", + RFC 4551, June 2006. + +10. 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. The participants of the IMAPext working group + made significant contributions to this work. + +Authors' Addresses + + Cyrus Daboo + Apple Inc. + 1 Infinite Loop + Cupertino, CA 95014 + USA + + EMail: cyrus@daboo.name + URI: http://www.apple.com/ + + + Randall Gellens + QUALCOMM Incorporated + 5775 Morehouse Dr. + San Diego, CA 92121-2779 + USA + + EMail: randy@qualcomm.com + + + + + + + + + + + + + + + +Daboo & Gellens Experimental [Page 30] + +RFC 5257 IMAP ANNOTATE Extension June 2008 + + +Full Copyright Statement + + Copyright (C) The IETF Trust (2008). + + This document is subject to the rights, licenses and restrictions + contained in BCP 78, and except as set forth therein, the authors + retain all their rights. + + This document and the information contained herein are provided on an + "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS + OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND + THE INTERNET ENGINEERING TASK FORCE DISCLAIM 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. + +Intellectual Property + + The IETF takes no position regarding the validity or scope of any + Intellectual Property Rights or other rights that might be claimed to + pertain to the implementation or use of the technology described in + this document or the extent to which any license under such rights + might or might not be available; nor does it represent that it has + made any independent effort to identify any such rights. Information + on the procedures with respect to rights in RFC documents can be + found in BCP 78 and BCP 79. + + Copies of IPR disclosures made to the IETF Secretariat and any + assurances of licenses to be made available, or the result of an + attempt made to obtain a general license or permission for the use of + such proprietary rights by implementers or users of this + specification can be obtained from the IETF on-line IPR repository at + http://www.ietf.org/ipr. + + The IETF invites any interested party to bring to its attention any + copyrights, patents or patent applications, or other proprietary + rights that may cover technology that may be required to implement + this standard. Please address the information to the IETF at + ietf-ipr@ietf.org. + + + + + + + + + + + + +Daboo & Gellens Experimental [Page 31] + |