Network Working Group C. Daboo
Internet-Draft Apple
Intended status: Standards Track December 22, 2007
Expires: June 24, 2008
IMAP METADATA Extension
draft-daboo-imap-annotatemore-12
Status of this Memo
By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79.
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.
This Internet-Draft will expire on June 24, 2008.
Copyright Notice
Copyright (C) The IETF Trust (2007).
Abstract
The METADATA extension to the Internet Message Access Protocol
permits clients and servers to maintain "annotations" or "meta data"
on IMAP servers. It is possible to have annotations on a per-mailbox
basis or on the server as a whole. For example, this would allow
comments about the purpose of a particular mailbox to be "attached"
to that mailbox, or a "message of the day" containing server status
information to be made available to anyone logging in to the server.
Daboo Expires June 24, 2008 [Page 1]
Internet-Draft IMAP METADATA Extension December 2007
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 . . . . . . . . . . . 5
3.2.1. Entry Names . . . . . . . . . . . . . . . . . . . . . 5
3.2.2. Attribute Names . . . . . . . . . . . . . . . . . . . 7
3.3. Private versus Shared and Access Control . . . . . . . . . 8
4. IMAP Protocol Changes . . . . . . . . . . . . . . . . . . . . 8
4.1. General Considerations . . . . . . . . . . . . . . . . . . 8
4.2. GETMETADATA Command . . . . . . . . . . . . . . . . . . . 9
4.3. Extended LIST Command Extensions . . . . . . . . . . . . . 11
4.3.1. Unsolicited LIST response . . . . . . . . . . . . . . 16
4.4. SETMETADATA Command . . . . . . . . . . . . . . . . . . . 16
4.5. METADATA Response . . . . . . . . . . . . . . . . . . . . 19
4.5.1. METADATA response with attributes and values . . . . . 19
4.5.2. Unsolicited METADATA response without attributes
and values . . . . . . . . . . . . . . . . . . . . . . 20
5. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . . 21
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23
6.1. Entry and Attribute Registration Template . . . . . . . . 23
6.2. Server Entry Registrations . . . . . . . . . . . . . . . . 23
6.2.1. /comment . . . . . . . . . . . . . . . . . . . . . . . 24
6.2.2. /motd . . . . . . . . . . . . . . . . . . . . . . . . 24
6.2.3. /admin . . . . . . . . . . . . . . . . . . . . . . . . 25
6.3. Mailbox Entry Registrations . . . . . . . . . . . . . . . 25
6.3.1. /comment . . . . . . . . . . . . . . . . . . . . . . . 25
6.3.2. /sort . . . . . . . . . . . . . . . . . . . . . . . . 26
6.3.3. /thread . . . . . . . . . . . . . . . . . . . . . . . 26
6.3.4. /check . . . . . . . . . . . . . . . . . . . . . . . . 27
6.3.5. /checkperiod . . . . . . . . . . . . . . . . . . . . . 27
6.4. LIST-EXTENDED Registration . . . . . . . . . . . . . . . . 27
7. Security Considerations . . . . . . . . . . . . . . . . . . . 28
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 29
8.1. Normative References . . . . . . . . . . . . . . . . . . . 29
8.2. Informative References . . . . . . . . . . . . . . . . . . 30
Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . . 30
Appendix B. Change History (to be removed prior to
publication as an RFC) . . . . . . . . . . . . . . . 30
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 33
Intellectual Property and Copyright Statements . . . . . . . . . . 34
Daboo Expires June 24, 2008 [Page 2]
Internet-Draft IMAP METADATA Extension December 2007
1. Introduction and Overview
The goal of the METADATA extension is to provide a means for clients
to set and retrieve "annotations" or "meta data" on an IMAP server.
The annotations can be associated with specific mailboxes or the
server as a whole. The server can choose to support only server
annotations or both server and mailbox annotations.
A server that supports both server and mailbox annotations indicates
the presence of this extension by returning "METADATA" as one of the
supported capabilities in the CAPABILITY command response. The
"LIST-EXTENDED" [I-D.ietf-imapext-list-extensions] and "ENABLE"
[I-D.gulbrandsen-imap-enable] extensions MUST also be present.
A server that supports only server annotations indicates the presence
of this extension by returning "METADATA-SERVER" as one of the
supported capabilities in the CAPABILITY command response. The
"ENABLE" [I-D.gulbrandsen-imap-enable] extension MUST also be
present. There is no requirement that other extensions, including
"LIST-EXTENDED", be present in this case.
The METADATA extension adds two new commands and one new untagged
response to the IMAP base protocol. It adds one new LIST-EXTENDED
"selection" [I-D.ietf-imapext-list-extensions] option type and one
new LIST-EXTENDED "return" [I-D.ietf-imapext-list-extensions] option
type.
This extension makes the following changes to the IMAP protocol:
For server annotations only:
* adds a new SETMETADATA command
* adds a new GETMETADATA command
* adds a new METADATA untagged response
* adds a new METADATA response code
For server and mailbox annotation support:
* adds a new SETMETADATA command
* adds a new GETMETADATA command
* adds a new METADATA untagged response
* adds a new METADATA response code
* adds a new METADATA LIST-EXTENDED selection option type
* adds a new METADATA LIST-EXTENDED return option type
The data model used in METADATA is exactly the same as that used in
the ANNOTATE [I-D.ietf-imapext-annotate] extension to IMAP. This is
modeled after that of the Application Configuration Access Protocol
Daboo Expires June 24, 2008 [Page 3]
Internet-Draft IMAP METADATA Extension December 2007
[RFC2244] with the exception of inheritance which is not deemed
necessary here.
Text comparisons may be done as part of the GETMETADATA or LIST-
EXTENDED commands. If the COMPARATOR [I-D.ietf-imapext-i18n]
extension is present, then comparisons are done using the comparator
in effect at the time. If the COMPARATOR extension is not present,
then comparisons MUST use the i;unicode-casemap comparator, as
defined in [RFC5051].
The rest of this document describes the data model and protocol
changes more rigorously.
2. Conventions Used in This Document
In examples, "C:" and "S:" 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].
Whitespace and line breaks have been added to the examples in this
document to promote readability.
3. Data Model
3.1. Overview
Mailboxes or the server as a whole may have zero or more annotations
associated with them. An annotation contains a uniquely named entry
with a set of uniquely named attributes, each of which has a value.
Annotations can be added to mailboxes when a mailbox name is provided
as the first argument to the new command, or to the server as a whole
when the empty string is provided as the first argument to the new
command.
For example, a general comment being added to a mailbox may have an
entry name of "/comment". This entry could include named attributes
such as "value" and "size" etc to represent properties and data
associated with the entry.
The protocol changes to IMAP described below allow a client to access
or change the values of any attributes in any annotation entry,
assuming it has sufficient access rights to do so.
Daboo Expires June 24, 2008 [Page 4]
Internet-Draft IMAP METADATA Extension December 2007
3.2. Namespace of entries and attributes
Each annotation is an entry that 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 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 NUL
octet. Invalid entry or attribute names result in a BAD response in
any IMAP commands where they are used.
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 with mailbox and server annotations. In
addition an extension mechanism is described to allow additional
names to be added for extensibility.
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.
3.2.1.1. Server Entries
These entries are used when the mailbox name argument to the new
SETMETADATA command is the empty string or with the new GETMETADATA
command.
/comment
Daboo Expires June 24, 2008 [Page 5]
Internet-Draft IMAP METADATA Extension December 2007
Defines a comment or note associated with the server.
/motd
Defines a "message of the day" for the server. This entry is
always read-only - clients cannot change it.
/admin
Indicates a method for contacting the server administrator. The
value MUST be a URI (e.g., a mailto: or tel: URL). This entry is
always read-only - clients cannot change it.
/vendor/<vendor-token>
Defines the top-level of entries associated with the server as
created by a particular product of some vendor. This entry can be
used by vendors to provide server or client specific annotations.
The vendor-token MUST be registered with IANA, using the ACAP
[RFC2244] vendor subtree registry.
3.2.1.2. Mailbox Entries
These entries are used when the mailbox name argument to the new
SETMETADATA command is not the empty string, or with the new LIST-
EXTENDED selection option type, or in responses to these commands.
/comment
Defines a comment or note associated with a mailbox.
/sort
Defines the default sort criteria [I-D.ietf-imapext-sort] to use
when first displaying the mailbox contents to the user, or NIL if
sorting is not required. The text value MUST use the 'sort-
criteria' syntax defined by the Formal Syntax of
[I-D.ietf-imapext-sort] Section 5. Note that the presence of this
attribute does not imply that the server supports the IMAP SORT
[I-D.ietf-imapext-sort] extension - servers can choose to support
or not support SORT independently of this extension. In the
absence of the SORT extension, clients can choose to interpret
this entry as suggesting a client-side sort ordering of the
corresponding mailbox.
/thread
Defines the default thread criteria [I-D.ietf-imapext-sort] to use
when first displaying the mailbox contents to the user, or NIL if
threading is not required. If both sort and thread are not NIL,
then threading should take precedence over sorting. The text
value MUST use the 'thread-alg' syntax defined by the Formal
Syntax of [I-D.ietf-imapext-sort] Section 5. Note that the
presence of this attribute does not imply that the server supports
Daboo Expires June 24, 2008 [Page 6]
Internet-Draft IMAP METADATA Extension December 2007
the IMAP THREAD [I-D.ietf-imapext-sort] extension - servers can
choose to support or not support THREAD independently of this
extension. In the absence of the THREAD extension, clients can
choose to interpret this entry as a client-side thread ordering of
the corresponding mailbox.
/check
Boolean value "true" or "false" that indicates whether this
mailbox should be checked at regular intervals by the client. The
interval in minutes is specified by the /checkperiod entry. When
appropriate clients SHOULD use the IMAP IDLE [RFC2177] extension
to poll the currently selected mailbox even when this value is set
to "true".
/checkperiod
Numeric value indicating a period of minutes that the client uses
to determine the interval of regular 'new mail' checks for the
corresponding mailbox.
/vendor/<vendor-token>
Defines the top-level of entries associated with a specific
mailbox 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, using
the ACAP [RFC2244] vendor subtree registry.
3.2.2. Attribute Names
This specification defines two attribute names. Each attribute name
implicitly has a ".priv" and a ".shared" suffix which maps to private
and shared versions of the entry. Retrieving an annotation without
using either suffix includes both. The client MUST specify either a
".priv" or ".shared" suffix when setting an annotation.
value
A string or binary data representing the value of the annotation.
To delete an annotation, the client can store "NIL" into 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] charset.
Note that binary data (data which may contain the NUL octet) is
allowed (e.g., for storing images etc), and this extension uses
the "literal8" syntax element [RFC4466] to allow such data to be
written to or read from the server.
size
Daboo Expires June 24, 2008 [Page 7]
Internet-Draft IMAP METADATA Extension December 2007
The size of the value, in octets. Set automatically by the
server, read-only to clients. The text value MUST use the
'number' syntax defined by the Formal Syntax of [RFC3501] Section
9. In particular neither "NIL" nor the empty string are allowed.
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 and Access Control
As discussed in the ANNOTATE [I-D.ietf-imapext-annotate] extension
there is a need to support both private and shared annotations. This
document adopts the scheme used in [I-D.ietf-imapext-annotate] that
adds two standard suffixes for all attributes: ".shared" and ".priv".
A GETMETADATA or extended LIST command which specifies neither uses
both. SETMETADATA commands MUST explicitly use .priv or .shared
suffixes.
A user can only set and retrieve private or shared annotations on a
mailbox which exists and is returned to them via a LIST or LSUB
command, irrespective of whether they have read or write access to
the actual message content of the mailbox. If the client attempts to
set or retrieve annotations on other mailboxes, the server MUST
respond with a NO response.
If the METADATA extension is present, support for shared annotations
is REQUIRED, whilst support for private annotations is OPTIONAL.
This recognizes the fact that support for private annotations may
introduce significantly more 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
METADATA extension MUST handle both shared and private annotations.
4. IMAP Protocol Changes
4.1. General Considerations
The new SETMETADATA command and the METADATA response each have a
mailbox name argument. An empty string is used for the mailbox name
to signify server annotations. A non-empty string is used to signify
mailbox annotations attached to the corresponding mailbox.
Both "*" and "%" list wildcard characters MAY be used in the mailbox
name argument in the SETMETADATA command to match all possible
occurrences of a mailbox name pattern. However, "*" or "%" by
themselves MUST NOT match the empty string (server) entries. Server
entries can only be accessed by explicitly using the empty string as
the mailbox name.
Daboo Expires June 24, 2008 [Page 8]
Internet-Draft IMAP METADATA Extension December 2007
Servers SHOULD ensure that mailbox annotations are automatically
moved when the mailbox they refer to is renamed, i.e. the annotations
follow the mailbox. This applies to a rename of the INBOX, with the
additional behavior that the annotations are copied from the original
INBOX to the renamed mailbox. i.e. mailbox annotations are preserved
on the INBOX when it is renamed.
Servers SHOULD delete annotations for a mailbox when the mailbox is
deleted, so that a mailbox created with the same name as a previously
existing mailbox does not inherit the old mailbox annotations.
Servers SHOULD allow annotations on all 'types' of mailbox, including
ones reporting \Noselect for their LIST response. Servers can
implicitly remove \Noselect mailboxes when all child mailboxes are
removed, and as such any annotations associated with the \Noselect
mailbox SHOULD be removed.
The server is allowed to impose limitations on the size of any one
annotation or the total number of annotations for a single mailbox or
for the server as a whole. However, the server MUST accept a minimum
annotation data size of at least 1024 bytes, and a minimum annotation
count per server or mailbox of at least 10.
Some annotations may be "read-only" - i.e. they are set by the server
and cannot be changed by the client. Also, such annotations may be
"computed" - i.e. the value changes based on underlying properties of
the mailbox. For example, an annotation reporting the total size of
all messages in the mailbox would change as messages are added or
removed. Or, an annotation containing an IMAP URL for the mailbox
would change if the mailbox was renamed.
This extension defines some unsolicited responses for use when
annotations are changed by some "third-party" (see Section 4.3.1 and
Section 4.5). The server MUST only send these unsolicited responses
if the client used the ENABLE command [I-D.gulbrandsen-imap-enable]
extension with the capability string "METADATA" earlier in the
session.
4.2. GETMETADATA Command
This extension adds the GETMETADATA command. This allows clients to
retrieve server annotations. Mailbox annotations are retrieved via
the extended LIST command described in the next section.
This command is only available in authenticated or selected state
[RFC3501].
Daboo Expires June 24, 2008 [Page 9]
Internet-Draft IMAP METADATA Extension December 2007
Arguments: entry-specifier
attribute-specifier
Responses: required METADATA response
Result: OK - command completed
NO - command failure: can't access annotations on
the server
BAD - command unknown or arguments invalid
Example:
C: a GETMETADATA /comment value.priv
S: * METADATA /comment (value.priv "My comment")
S: a OK GETMETADATA complete
In the above example, the contents of the "value.priv" attribute
for the "/comment" server entry is requested by the client and
returned by the server.
"*" and "%" wildcard characters can be used in the entry specifier to
match one or more characters at that position, with the exception
that "%" does not match the "/" hierarchy delimiter. Thus an entry
specifier of "/%" would match entries such as "/comment" and "/motd",
but not "/comment/note".
Example:
C: a GETMETADATA /* value.priv
S: * METADATA /comment (value.priv "My comment")
/motd (value.priv "Closed at 1 pm")
S: a OK GETMETADATA complete
In the above example, the contents of the "value.priv" attributes
for any server entries are requested by the client and returned by
the server.
Example:
C: a GETMETADATA /% value
S: * METADATA /comment (value.priv "My comment")
(value.shared "Your comment")
/motd (value.priv "Its sunny outside!"
(value.shared "Today is a Holiday")
S: a OK GETMETADATA complete
Daboo Expires June 24, 2008 [Page 10]
Internet-Draft IMAP METADATA Extension December 2007
In the above example, the contents of the "value" attributes for
server entries at the top level of the entry hierarchy only, are
requested by the client and returned by the server. Both the
.priv and .shared values are returned, as neither were explicitly
requested.
Entry and attribute specifiers can be lists of atomic specifiers, so
that multiple items of each type may be returned in a single
GETMETADATA command.
Example:
C: a GETMETADATA (/comment /motd) value.priv
S: * METADATA /comment (value.priv "My comment")
/motd (value.priv "Its sunny outside!")
S: a OK GETMETADATA complete
In the above example, the contents of the "value.priv" attributes
for the two server entries "/comment" and "/motd" are requested by
the client and returned by the server.
Example:
C: a GETMETADATA /comment (value.priv
size.priv)
S: * METADATA /comment (value.priv "My comment"
size.priv "10")
S: a OK GETMETADATA complete
In the above example, the contents of the "value.priv" and
"size.priv" attributes for the "/comment" server entry are
requested by the client and returned by the server.
4.3. Extended LIST Command Extensions
This extension adds the METADATA LIST command selection and return
option types, extending the LIST-EXTENDED extension. This allows
clients to retrieve mailbox annotations.
The LIST-EXTENDED "METADATA" selection option type is used to request
that the extended LIST command match mailboxes which have an
annotation with a specific entry and value. It can also be used to
test for the existence of a particular annotation entry on a mailbox.
This selection option takes one or more entry/attribute/value triples
to use as tests. A mailbox matches this criteria if it has an entry,
attribute and value matching the ones specified. In the case of
multiple criteria being specified, mailbox MUST only match when all
criteria match ("and" operation). To test for the existence of an
Daboo Expires June 24, 2008 [Page 11]
Internet-Draft IMAP METADATA Extension December 2007
entry, a test for the attribute "value" with the empty string "" as
the value argument can be used. To test for the absence of an entry,
a test for the attribute "value" with NIL as the value argument can
be used. Clients SHOULD only use entries defined with a "text"
Content-Type in the selection option arguments.
Each entry/attribute/value triple specified in the selection option
MAY include a match type specifier and MAY include a collation
[I-D.ietf-imapext-i18n] identifier. If the match type is specified,
then that match operation MUST be used when matching the provided
value with the corresponding annotation entry values in mailboxes.
If the match type is not specified, then a default of "CONTAINS"
(substring match) MUST be used. If the collation identifier is
specified, then that collation MUST be used to do the comparison of
the annotation entry values being tested. If the collation
identifier is not specified, then the active collation as defined by
[I-D.ietf-imapext-i18n] is used. If the client specifies a collation
identifier not known to the server, the server MUST return a BAD
response. Possible values for the match type are:
+----------+-----------------------------------------------+
| Match | Description |
+----------+-----------------------------------------------+
| IS | Equality test is done |
| CONTAINS | Substring match is done |
| GT | Greater than relational test is done |
| GE | Greater than or equal relational test is done |
| LE | Less than or equal relational test is done |
| LT | Less than relational test is done |
+----------+-----------------------------------------------+
The "NOT" match type modifier results in a negation of the comparison
- i.e. it adds the ability to search for annotations that do not
match or contain specific text.
The LIST-EXTENDED "METADATA" return option type is used to request
that the extended LIST command return specific annotation entries for
each mailbox returned in the LIST responses. A list of entries and
attributes to return can be specified in a manner similar to the
GETMETADATA command.
Example:
C: a LIST "" "INBOX" RETURN (METADATA (/comment value.priv))
S: * LIST "/" "INBOX"
(METADATA (/comment (value.priv "My comment")))
S: a OK LIST complete
Daboo Expires June 24, 2008 [Page 12]
Internet-Draft IMAP METADATA Extension December 2007
In the above example, the contents of the "value.priv" attribute
for the "/comment" entry for the mailbox INBOX is requested by the
client and returned by the server.
"*" and "%" wildcard characters can be used in the entry specifier to
match one or more characters at that position, with the exception
that "%" does not match the "/" hierarchy delimiter. Thus an entry
specifier of "/%" would match entries such as "/comment" and
"/check", but not "/comment/note".
Example:
C: a LIST "" "INBOX" RETURN (METADATA (/* value.priv))
S: * LIST "/" "INBOX"
(METADATA (/comment (value.priv "My comment")
/check (value.priv "true")))
S: a OK LIST complete
In the above example, the contents of the "value.priv" attributes
for any entries for the mailbox INBOX are requested by the client
and returned by the server.
Example:
C: a LIST "" "INBOX" RETURN (METADATA (/% value))
S: * LIST "/" "INBOX"
(METADATA (/comment (value.priv "My comment")
(value.shared "Your comment")
/motd (value.priv "Its sunny outside!"
(value.shared "Today is a Holiday")))
S: a OK LIST complete
In the above example, the contents of the "value" attributes for
entries for the mailbox INBOX at the top level of the entry
hierarchy only, are requested by the client and returned by the
server. Both the .priv and .shared values are returned, as
neither were explicitly requested.
Entry and attribute specifiers can be lists of atomic specifiers, so
that multiple items of each type may be returned in a single LIST
command.
Example:
Daboo Expires June 24, 2008 [Page 13]
Internet-Draft IMAP METADATA Extension December 2007
C: a LIST "" "INBOX" RETURN (METADATA ((/comment /motd)
value.priv))
S: * LIST "/" "INBOX"
(METADATA (/comment (value.priv "My comment")
/motd (value.priv "Its sunny outside!")))
S: a OK LIST complete
In the above example, the contents of the "value.priv" attributes
for the two entries "/comment" and "/motd" for the mailbox INBOX
are requested by the client and returned by the server.
Example:
C: a LIST "" "INBOX" RETURN (METADATA (/comment
(value.priv size.priv)))
S: * LIST "/" "INBOX"
(METADATA (/comment (value.priv "My comment"
size.priv "10")))
S: a OK LIST complete
In the above example, the contents of the "value.priv" and
"size.priv" attributes for the "/comment" entry for the mailbox
INBOX are requested by the client and returned by the server.
Example:
C: a LIST "" ("INBOX" "FOOBOX" "BARBOX") RETURN
(METADATA (/comment value.priv))
S: * LIST "/" "INBOX"
(METADATA (/comment (value.priv "My comment")))
S: * LIST "/" "FOOBOX"
(METADATA (/comment (value.priv "Another comment")))
S: * LIST "/" "BARBOX"
(METADATA (/comment (value.priv NIL)))
S: a OK LIST complete
In the above example, the contents of the "value.priv" attribute
for the "/comment" entry for the mailboxes INBOX, FOOBOX and
BARBOX are requested by the client and returned by the server.
Note that the mailbox BARBOX does not contain the entry, hence NIL
is returned for the attribute value.
Example:
C: a LIST (METADATA ("/comment" "value" "comm"
(NOT CONTAINS))) "" "*"
S: * LIST () "/" "INBOX"
S: * LIST (\NoInferiors) "/" "FOOBOX"
Daboo Expires June 24, 2008 [Page 14]
Internet-Draft IMAP METADATA Extension December 2007
S: a OK LIST complete
In the above example, the client requests that any mailbox in the
entire hierarchy that does not contain the text "comm" in any
"value" attribute of the "/comment" entry be returned. Two
mailboxes are returned in separate responses. Note that the
client did not ask for annotations to be returned in the
responses.
Example:
C: a LIST (METADATA ("/comment" "value" ""))
"" "*"
S: * LIST () "/" "INBOX"
S: * LIST (\NoInferiors) "/" "FOOBOX"
S: a OK LIST complete
In the above example, the client requests that any mailbox in the
entire hierarchy containing the "/comment" entry be returned. Two
mailboxes are returned in separate responses. Note that the
client did not ask for annotations to be returned in the
responses.
Example:
C: a LIST (METADATA ("/comment" "value" NIL))
"" "*"
S: * LIST (\NoInferiors) "/" "BARBOX"
S: a OK LIST complete
In the above example, the client requests that any mailbox in the
entire hierarchy that does not have a "/comment" entry be
returned. One mailbox is returned in a response. Note that the
client did not ask for annotations to be returned in the
responses.
Example:
C: a LIST (METADATA ("/comment" "value" "HELP"
(IS "i;octet")) "" "*"
RETURN (METADATA (/comment size.priv))
S: * LIST "/" "INBOX"
(METADATA (/comment (size.priv "10")))
S: * LIST "/" "FOOBOX"
(METADATA (/comment (size.priv "15")))
S: a OK LIST complete
Daboo Expires June 24, 2008 [Page 15]
Internet-Draft IMAP METADATA Extension December 2007
In the above example, the client requests that any mailbox in the
entire hierarchy with the exact text "HELP" in any "value"
attribute of the "/comment" entry be returned. The client
provides an explicit match type and collation identifier. Two
mailboxes are returned in separate responses. The client also
asked for annotation sizes to be returned in the responses.
4.3.1. Unsolicited LIST response
Subject to unsolicited responses being activated by the ENABLE
[I-D.gulbrandsen-imap-enable] command for this extension, servers
SHOULD send unsolicited LIST responses if mailbox annotations are
changed by a third-party, allowing servers to keep clients updated
with changes. Unless explicitly changed by an IMAP extension,
unsolicited mailbox annotations MUST only be returned for the
currently selected mailbox.
Unsolicited LIST responses MUST only contain entry names, not the
attributes and values. If the client wants to update any cached
values it must explicitly retrieve those using a LIST command.
The LIST response can contain multiple entries in a single response,
but the server is free to return multiple responses for each entry or
group of entries if it desires.
Example:
C: a NOOP
S: * LIST "/" "INBOX" (METADATA (/comment))
S: a OK NOOP complete
In the above example, the server sends an unsolicited LIST
response indicating that the "/comment" entry of the mailbox
"INBOX" has been changed.
4.4. SETMETADATA Command
This extension adds the SETMETADATA command. This allows clients to
set annotations.
This command is only available in authenticated or selected state
[RFC3501].
Daboo Expires June 24, 2008 [Page 16]
Internet-Draft IMAP METADATA Extension December 2007
Arguments: mailbox-name
entry
attribute-value
list of entry, attribute-values
Responses: no specific responses for this command
Result: OK - command completed
NO - command failure: can't set annotations,
or annotation too big or too many
BAD - command unknown or arguments invalid
This command sets the specified list of entries by adding or
replacing the specified attributes with the values provided, on the
specified existing mailboxes or on the server (if the mailbox
argument is the empty string). Clients can use NIL for values of
attributes it wants to remove from entries. The server SHOULD NOT
return a METADATA or LIST response containing the updated annotation
data. Clients MUST NOT assume that a METADATA or LIST response will
be sent, and MUST assume that if the command succeeds then the
annotation has been changed.
If the server is unable to set an annotation because the size of its
value is too large, the server MUST return a tagged NO response with
a "[METADATA TOOBIG]" response code.
If the server is unable to set a new annotation because the maximum
number of allowed annotations has already been reached, the server
MUST return a tagged NO response with a "[METADATA TOOMANY]" response
code.
If the server is unable to set a new annotation because it does not
support private annotations on one of the specified mailboxes, the
server MUST return a tagged NO response with a "[METADATA NOPRIVATE]"
response code.
Example:
C: a SETMETADATA INBOX /comment
(value.priv "My new comment")
S: a OK SETMETADATA complete
In the above example, the entry "/comment" for the mailbox "INBOX"
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 previously exists.
Example:
Daboo Expires June 24, 2008 [Page 17]
Internet-Draft IMAP METADATA Extension December 2007
C: a SETMETADATA INBOX /comment (value.priv NIL)
S: a OK SETMETADATA complete
In the above example, the private "value" attribute of the entry
"/comment" is removed from the mailbox "INBOX".
Annotations on multiple mailboxes can be set in a single SETMETADATA
command by using a wildcard specification for the mailbox name.
Example:
C: a SETMETADATA INBOX.% /comment
(value.priv "My new comment")
S: a OK SETMETADATA complete
In the above example, the entry "/comment" for all mailboxes at
the top-level of the "INBOX" hierarchy are created (if not already
present) and the private attribute "value" are created
respectively for each entry if not already present, or replaced if
they previously existed.
Multiple entries can be set in a single SETMETADATA command by
listing entry-attribute-value pairs in the list.
Example:
C: a SETMETADATA INBOX (/comment
(value.priv "My new comment")
/thread
(value.priv "REFERENCES ALL"))
S: a OK SETMETADATA complete
In the above example, the entries "/comment" and "/thread" for the
mailbox "INBOX" are created (if not already present) and the
"value.priv" attributes are created respectively for each entry if
not already present, or replaced if they previously existed.
Multiple attributes can be set in a single SETMETADATA command by
listing multiple attribute-value pairs in the entry list.
Example:
C: a SETMETADATA INBOX /comment
(value.priv "My new comment"
value.shared "foo's bar")
S: a OK SETMETADATA complete
Daboo Expires June 24, 2008 [Page 18]
Internet-Draft IMAP METADATA Extension December 2007
In the above example, the entry "/comment" for the mailbox "INBOX"
is created (if not already present) and the attributes
"value.priv" and "value.shared" are created if not already
present, or replaced if they previously existed.
Example:
C: a SETMETADATA INBOX /comment
(value.priv "My new comment")
S: a NO [METADATA TOOMANY] SETMETADATA failed
In the above example, the server is unable to set the requested
(new) annotation as it has reached the limit on the number of
annotations it can support on the specified mailbox.
4.5. METADATA Response
The METADATA response displays results of a GETMETADATA command, or
can be returned as an unsolicited response at anytime by the server
in response to a change in a server annotation.
Subject to unsolicited responses being activated by the ENABLE
[I-D.gulbrandsen-imap-enable] command for this extension, servers
SHOULD send unsolicited METADATA responses if server annotations are
changed by a third-party, allowing servers to keep clients updated
with changes.
Unsolicited METADATA responses MUST only contain entry names, not the
attributes and values. If the client wants to update any cached
values it must explicitly retrieve those using a GETMETADATA command.
The METADATA response can contain multiple entries in a single
response, but the server is free to return multiple responses for
each entry or group of entries if it desires.
This response is only available in authenticated or selected state
[RFC3501].
4.5.1. METADATA response with attributes and values
The response consists of a list of entries each of which has a list
of attribute-value pairs.
Example:
C: a GETMETADATA /comment value.priv
S: * METADATA /comment (value.priv "My comment")
S: a OK GETMETADATA complete
Daboo Expires June 24, 2008 [Page 19]
Internet-Draft IMAP METADATA Extension December 2007
In the above example, a single entry with a single attribute-value
pair is returned by the server.
Example:
C: a GETMETADATA (/comment /motd) value.priv
S: * METADATA /comment (value.priv "My comment")
/motd (value.priv "Its sunny outside!")
S: a OK GETMETADATA complete
In the above example, two entries each with a single attribute-
value pair is returned by the server.
Example:
C: a GETMETADATA (/comment /motd) value.priv
S: * METADATA /comment (value.priv "My comment")
S: * METADATA /motd (value.priv "Its sunny outside!")
S: a OK GETMETADATA complete
In the above example, the server returns two separate responses
for each of the two entries requested.
Example:
C: a GETMETADATA /comment (value.priv size.priv)
S: * METADATA /comment (value.priv "My comment"
size.priv "10")
S: a OK GETMETADATA complete
In the above example, a single entry with two attribute-value
pairs is returned by the server.
4.5.2. Unsolicited METADATA response without attributes and values
The response consists of a parenthesized list of entries, each of
which have changed on the server.
Example:
C: a NOOP
S: * METADATA (/comment)
S: a OK NOOP complete
In the above example, the server indicates that the "/comment"
server entry has been changed.
Example:
Daboo Expires June 24, 2008 [Page 20]
Internet-Draft IMAP METADATA Extension December 2007
C: a NOOP
S: * METADATA (/comment /motd)
S: a OK NOOP complete
In the above example, the server indicates a change to two server
entries.
5. Formal Syntax
The following syntax specification uses the Augmented Backus-Naur
Form (ABNF) notation as specified in [RFC4234].
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.
annotate-data = "METADATA" SP entry-list
att-select = "value" / "value.priv" / "value.shared"
; the only attributes that can be selected
att-value = attrib SP value
attrib = astring
; dot-separated attribute name
; MUST NOT contain "*" or "%"
attribs = attrib / "(" attrib *(SP attrib) ")"
; one or more attribute specifiers
capability =/ "METADATA" / "METADATA-SERVER"
; defines the capabilities for this extension
command-auth =/ setmetadata / getmetadata
; adds to original IMAP command
collation = astring
; collation identifier as defined by
; [RFC4790]
entries = entry-match /
"(" entry-match *(SP entry-match) ")"
Daboo Expires June 24, 2008 [Page 21]
Internet-Draft IMAP METADATA Extension December 2007
; entry specifiers that can include wildcards
entry = astring
; slash-separated path to entry
; MUST NOT contain "*" or "%"
entry-att = entry SP "(" att-value *(SP att-value) ")"
entry-list = entry-att *(SP entry-att) /
"(" entry *(SP entry) ")"
; entry attribute-value pairs list for
; GETMETADATA response, or
; parenthesised entry list for unsolicited
; notification of annotation changes
entry-match = list-mailbox
; slash-separated path to entry
; MAY contain "*" or "%" for use as wildcards
getmetadata = "GETMETADATA" SP entries SP attribs
list-select-base-opt =/ "METADATA" SP
"(" list-select-metadata
*(SP list-select-metadata) ")"
; adds a new selection option type to
; LIST-EXTENDED. When evaluating multiple entry,
; attribute, value combinations, a match to
; a mailbox must occur when all items match.
list-select-metadata = entry-match SP att-select SP value
[SP "(" matchtype [SP collation] ")"]
; value set to the empty string means match
; if that entry and attribute exist.
; value set to NIL means match if that entry
; and attribute do not exist.
; An optional match type and collation can also
; be specified.
matchtype = ["NOT" SP] ("IS" / "CONTAINS" /
"GT" / "GE" / "LE" / "LT")
; match types for LIST-EXTENDED string
; comparisons - see Section 4.3.
response-payload =/ annotate-data
; adds to original IMAP data responses
resp-text-code =/ "METADATA" SP ("TOOBIG" / "TOOMANY" /
Daboo Expires June 24, 2008 [Page 22]
Internet-Draft IMAP METADATA Extension December 2007
"NOPRIVATE")
; new response codes for SETMETADATA
; failures
setmetadata = "SETMETADATA" SP list-mailbox
SP setentryatt
; empty string for list-mailbox implies
; server annotation.
setentryatt = entry-att / "(" entry-att *(SP entry-att) ")"
value = nstring / literal8
6. IANA Considerations
Entry names MUST be specified in a standards track or IESG approved
experimental RFC, or fall under the vendor namespace.
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 METADATA Entry Registration
Type: [Either "Mailbox" or "Server"]
Name: [the name of the entry]
Description: [a description of what the entry is for]
Content-type: [MIME Content-Type and charset for the entry value]
RFC Number: [for entries published as RFCs]
Contact: [email and/or physical address to contact for
additional information]
6.2. Server Entry Registrations
The following templates specify the IANA registrations of annotation
entries specified in this document.
Daboo Expires June 24, 2008 [Page 23]
Internet-Draft IMAP METADATA Extension December 2007
6.2.1. /comment
To: iana@iana.org
Subject: IMAP METADATA Entry Registration
Type: Server
Name: /comment
Description: Defined in IMAP METADATA extension document.
Content-type: text/plain; charset=utf-8
RFC Number: This RFC.
Contact: IMAP Extensions <ietf-imapext@imc.org>
6.2.2. /motd
To: iana@iana.org
Subject: IMAP METADATA Entry Registration
Type: Server
Name: /motd
Description: Defined in IMAP METADATA extension document.
Content-type: text/plain; charset=utf-8
RFC Number: This RFC.
Contact: IMAP Extensions <ietf-imapext@imc.org>
Daboo Expires June 24, 2008 [Page 24]
Internet-Draft IMAP METADATA Extension December 2007
6.2.3. /admin
To: iana@iana.org
Subject: IMAP METADATA Entry Registration
Type: Server
Name: /admin
Description: Defined in IMAP METADATA extension document.
Content-type: text/plain; charset=utf-8
RFC Number: This RFC.
Contact: IMAP Extensions <ietf-imapext@imc.org>
6.3. Mailbox Entry Registrations
The following templates specify the IANA registrations of annotation
entries specified in this document.
6.3.1. /comment
To: iana@iana.org
Subject: IMAP METADATA Entry Registration
Type: Mailbox
Name: /comment
Description: Defined in IMAP METADATA extension document.
Content-type: text/plain; charset=utf-8
RFC Number: This RFC.
Contact: IMAP Extensions <ietf-imapext@imc.org>
Daboo Expires June 24, 2008 [Page 25]
Internet-Draft IMAP METADATA Extension December 2007
6.3.2. /sort
To: iana@iana.org
Subject: IMAP METADATA Entry Registration
Type: Mailbox
Name: /sort
Description: Defined in IMAP METADATA extension document.
Content-type: text/plain; charset=utf-8
RFC Number: This RFC.
Contact: IMAP Extensions <ietf-imapext@imc.org>
6.3.3. /thread
To: iana@iana.org
Subject: IMAP METADATA Entry Registration
Type: Mailbox
Name: /thread
Description: Defined in IMAP METADATA extension document.
Content-type: text/plain; charset=utf-8
RFC Number: This RFC.
Contact: IMAP Extensions <ietf-imapext@imc.org>
Daboo Expires June 24, 2008 [Page 26]
Internet-Draft IMAP METADATA Extension December 2007
6.3.4. /check
To: iana@iana.org
Subject: IMAP METADATA Entry Registration
Type: Mailbox
Name: /check
Description: Defined in IMAP METADATA extension document.
Content-type: text/plain; charset=utf-8
RFC Number: This RFC.
Contact: IMAP Extensions <ietf-imapext@imc.org>
6.3.5. /checkperiod
To: iana@iana.org
Subject: IMAP METADATA Entry Registration
Please register the following IMAP METADATA entry:
Type: Mailbox
Name: /checkperiod
Description: Defined in IMAP METADATA extension document.
Content-type: text/plain; charset=utf-8
RFC Number: This RFC.
Contact: IMAP Extensions <ietf-imapext@imc.org>
6.4. LIST-EXTENDED Registration
To: iana@iana.org
Subject: Registration of LIST-EXTENDED option METADATA
LIST-EXTENDED option name: METADATA
LIST-EXTENDED option type: SELECTION
Implied return options(s): (none)
LIST-EXTENDED option description:
Daboo Expires June 24, 2008 [Page 27]
Internet-Draft IMAP METADATA Extension December 2007
The "METADATA" selection option type is used to request
that the extended LIST command match mailboxes which have
an annotation with a specific entry and value. It can
also be used to test for the existence of a particular
annotation entry on a mailbox.
Published specification : XXXX, Section 4.3.
Security considerations: XXXX, Section 7.
Intended usage: COMMON
Person and email address to contact for further information:
IMAP Extensions <ietf-imapext@imc.org>
Owner/Change controller: iesg@ietf.org
To: iana@iana.org
Subject: Registration of LIST-EXTENDED option METADATA
LIST-EXTENDED option name: METADATA
LIST-EXTENDED option type: RETURN
LIST-EXTENDED option description: Causes the LIST command to
return the specified mailbox annotations.
Published specification : XXXX, Section 4.3.
Security considerations: XXXX, Section 7.
Intended usage: COMMON
Person and email address to contact for further information:
IMAP Extensions <ietf-imapext@imc.org>
Owner/Change controller: iesg@ietf.org
7. Security Considerations
Annotations whose values are intended to remain private MUST use
.priv values, and not .shared values which may be accessible to other
users.
Annotations can contain arbitrary sized data. As such servers MUST
Daboo Expires June 24, 2008 [Page 28]
Internet-Draft IMAP METADATA Extension December 2007
ensure that size limits are enforced to prevent a user from using up
all available space on a server and preventing use by others.
Excluding the above issues the METADATA extension does not raise any
security considerations that are not present in the base IMAP
protocol, and these issues are discussed in [RFC3501].
8. References
8.1. Normative References
[I-D.gulbrandsen-imap-enable]
Gulbrandsen, A. and A. Melnikov, "The IMAP ENABLE
Extension", draft-gulbrandsen-imap-enable-05 (work in
progress), December 2007.
[I-D.ietf-imapext-i18n]
Newman, C., Gulbrandsen, A., and A. Melnikov, "Internet
Message Access Protocol Internationalization",
draft-ietf-imapext-i18n-14 (work in progress),
December 2007.
[I-D.ietf-imapext-list-extensions]
Leiba, B. and A. Melnikov, "IMAP4 LIST Command
Extensions", draft-ietf-imapext-list-extensions-18 (work
in progress), September 2006.
[I-D.ietf-imapext-sort]
Crispin, M. and K. Murchison, "INTERNET MESSAGE ACCESS
PROTOCOL - SORT AND THREAD EXTENSIONS",
draft-ietf-imapext-sort-19 (work in progress),
September 2007.
[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.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, November 2003.
[RFC4234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", RFC 4234, October 2005.
Daboo Expires June 24, 2008 [Page 29]
Internet-Draft IMAP METADATA Extension December 2007
[RFC4466] Melnikov, A. and C. Daboo, "Collected Extensions to IMAP4
ABNF", RFC 4466, April 2006.
[RFC4790] Newman, C., Duerst, M., and A. Gulbrandsen, "Internet
Application Protocol Collation Registry", RFC 4790,
March 2007.
[RFC5051] Crispin, M., "i;unicode-casemap - Simple Unicode Collation
Algorithm", RFC 5051, October 2007.
8.2. Informative References
[I-D.ietf-imapext-annotate]
Gellens, R. and C. Daboo, "IMAP ANNOTATE Extension",
draft-ietf-imapext-annotate-16 (work in progress),
October 2006.
[RFC2177] Leiba, B., "IMAP4 IDLE command", RFC 2177, June 1997.
Appendix A. Acknowledgments
The ideas expressed in this document are based on the message
annotation document that was co-authored by Randall Gellens. The
participants of the IMAPext working group made significant
contributions to this work.
Appendix B. Change History (to be removed prior to publication as an
RFC)
Changes from -11 to -12:
1. Allow server annotations to be used without mailbox annotations.
2. Require i;unicode-casemap when COMPARATOR is not present.
3. Use ENABLE to turn on unsolicited responses.
4. Use formal syntax elements from SORT/THREAD extensions to define
the values for /sort and /thread entries.
5. Added a comment that use of IDLE is preferred even when /check
is true.
6. Use formal syntax element from base spec for the /size value.
7. Removed IANA registration for attributes as we don't expect any
more to be defined.
8. Tweaked IANA registration template to be more compact and add
RFC Number reference.
9. Some minor re-phrasing was done.
10. Added text about handling of annotations on INBOX when it is
renamed.
Daboo Expires June 24, 2008 [Page 30]
Internet-Draft IMAP METADATA Extension December 2007
11. Require a BAD response when an unknown collation is used in
LISTEXT selection option.
Changes from -10 to -11:
1. Added new paragraph to indicate that values may be read-only or
computed.
2. /admin server annotation value now must be a URI.
3. Clarified that SORT and THREAD extensions are not required.
4. Fixed use of undefined entries in some examples.
5. Fixed many examples.
6. Added IANA registration for LIST-EXTENDED items.
7. Added match type and collation identifier to the LIST-EXTENDED
selection option.
8. Made support for IMAP-I18N a requirement.
9. Minor text clarifications applied.
10. Remove mailbox list set atomicity requirement.
11. Clarified that annotations can only be set on mailboxes that
actually exist.
Changes from -09 to -10:
1. Updated to rfc 4466 reference.
2. Reworded data model description.
3. Reworked LIST-EXTENDED so that responses have metadata items
after the mailbox info.
4. Various spelling fixes.
Changes from -08 to -09:
1. Remove content-language attribute and reference.
2. Changed capability and command names.
3. Revised abstract.
Changes from -07 to -08:
1. Changed 'string' formal syntax to 'list-mailbox' and 'astring'
for entry/attribute names.
2. Updated examples to match new astring syntax.
3. Changed CAPABILITY name due to incompatible syntax change.
4. Removed content-type attribute.
5. Added Content-type to IANA registration for entries.
6. Removed vendor attributes.
7. Fixed examples in section 3.3 for multi-mailbox and multi-entry
cases.
8. Removed wildcards for attributes.
9. Entry/attributes can now only be ASCII.
10. Tied up text wrt storing/fetching.
11. Added Conventions section
12. Entry/attributes MUST NOT contain consecutive or trailing '/' or
'.'.
Daboo Expires June 24, 2008 [Page 31]
Internet-Draft IMAP METADATA Extension December 2007
13. Changed to use IMAP ABNF extensions document for some formal
syntax items.
Changes from -06 to -07:
1. Reworded /checkperiod item.
2. Clarified unsolicited response behavior.
Changes from -05 to -06:
1. Removed 'modifiedsince' attribute as there is currently no use
for it.
2. Added content-language attribute.
3. Changed access to allow .priv and .shared on any mailbox returned
by LIST/LSUB.
4. Added IANA registrations for items defined in this document.
5. Added latest IPR statement.
6. Updated references.
Changes from -04 to -05:
1. Fix for valid IMAP state of commands.
2. Fix formatting, ID nits etc.
Changes from -03 to -04:
1. Allow retrieval of shared annotations for READ-ONLY mailbox.
2. Clarification of annotation loss on implicit removal of \Noselect
mailboxes.
3. Now requires roll-back of all changes to matching mailboxes if
there is a partial failure in SETANNOTATION.
Changes from -02 to -03:
1. Reworked entry naming scheme to split out mailbox name and use
empty string for server items.
Changes from -01 to -02:
1. SETANNOTATION lists use (..).
2. Explicitly state behavior of unsolicited responses.
3. Adding SHOULD behavior for rename/delete of mailboxes.
4. Added statement about supporting annotations on \Noselect
mailboxes.
5. Cleaned up formal syntax to use IMAP string type for entry and
attributes, with requirements on how the string is formatted.
6. Use of ACAP vendor subtree registry for vendor tokens.
Changes from -00 to -01:
1. Multiple entry-att responses are now simply delimited by spaces
in line with ANNOTATE spec. Adjusted examples to match.
2. Fixed entry-list formal syntax item to account for unsolicited
parenthesized list of entries.
Daboo Expires June 24, 2008 [Page 32]
Internet-Draft IMAP METADATA Extension December 2007
3. Removed setentries formal syntax item for simplicity since its
only used once.
4. Removed reference to 'message annotation' in section 5.1.
5. Changed formal syntax to restrict top level entries to /server
and /mailbox/{...} only. Re-arranged entry names section to
account for this change.
6. Added comment and example for ANNOTATION response to allow
servers to return separate responses for each entry if desired.
Author's Address
Cyrus Daboo
Apple Inc.
1 Infinite Loop
Cupertino, CA 95014
USA
Email: cyrus@daboo.name
URI: http://www.apple.com/
Daboo Expires June 24, 2008 [Page 33]
Internet-Draft IMAP METADATA Extension December 2007
Full Copyright Statement
Copyright (C) The IETF Trust (2007).
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.
Acknowledgment
Funding for the RFC Editor function is provided by the IETF
Administrative Support Activity (IASA).
Daboo Expires June 24, 2008 [Page 34]
