sender
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...
o error -- An error has occurred related to a previous message sent
by the sender (for details regarding stanza error syntax, refer to
[XMPP-CORE ...
... client SHOULD present an appropriate
interface informing the sender of the nature of the error.
o groupchat -- The message is sent in the context ...
... between two entities. The value of the <thread/> element is
generated by the sender and SHOULD be copied back in any replies. If
used, it MUST be unique to that conversation thread within the stream
...
... presence stanza is OPTIONAL. A presence
stanza that does not possess a 'type' attribute is used to signal to
the server that the sender is online and available for communication.
If included, the 'type' attribute specifies a lack of availability, a
request to manage a subscription to another entity ...
... presence.
o subscribed -- The sender has allowed the recipient to receive
their presence.
...
... entity. As defined under Server Rules for Handling XML Stanzas
(Section 11), the sender's server is responsible for delivering the
message to the intended recipient (if the recipient is on the same
server) or for routing ...
... a message by providing the JID of an entity other than the sender in
the 'to' attribute of the <message/> stanza. If the message is being
...
... domain/resource> rather than of the form <user@domain> unless
the sender has knowledge (via presence) that the intended recipient's
resource is no longer available. If the message is being sent
...
... A server MUST ignore any 'to' address on a roster "set", and MUST
treat any roster "set" as applying to the sender. For added safety,
a client SHOULD check the "from" address ...
... unavailable/> stanza error to
the sender if it is an IQ stanza, and (c) SHOULD return a
<service ...
... service-unavailable/> stanza error to the sender if it is an
IQ stanza, and (c) SHOULD treat the stanza ...
... email account).
However, if offline message storage or message forwarding is
not enabled, the server MUST return to the sender a
<service-unavailable ...
... whose intended recipient is a user associated with one of the
server's hostnames, the server MUST NOT reveal the user's presence
information if the sender is an entity that is not authorized to
receive that information as determined by presence subscriptions ...