Given feedback and implementation experience, here are some thoughts filling in parts of the Jingle state machine related to when and how certain actions can be performed. These things are implied by the XEP once various rules are applied, but they aren't explicitly stated.
The XEP does call out that
session-accept implicitly also acts as a
content-accept. However, that principle also applies to
session-terminate, even though the XEP does not make note of it.