routing
Click on the red underlined text to get to the source
... semantics of priority values in stanza routing within
instant messaging and presence applications, refer to Server Rules
...
... sender's server is responsible for delivering the
message to the intended recipient (if the recipient is on the same
server) or for routing the message to the recipient's server (if the
recipient is on a different server).
...
... Privacy lists MUST be the first delivery rule applied by a
server, superseding (1) the routing and delivery rules specified
in Server Rules for Handling XML Stanzas ...
... domain's stanza routing rules at all times), the user MUST send an
empty <default/> element with no 'name' attribute.
...