no explanation/documentation for subscribe, unsubscribe, get, put, list in deltas

[bkp7]

The delta.json schema has a mandatory section updates which is documented and being used in the wild. It also has the following sections which are optional:
subscribe - appears to duplicate parts of subscribe.json
unsubscribe - appears to duplicate parts of unsubscribe.json
put - see #442 for discussion on the proposed use of this
get, list - can't find any documentation

Do we really need 2 different specifications for subscribe and unsubscribe? Does a server have to implement both?

The put section has no explanation as to how this will work and what the response will be (although #442 is working towards it)

None of subscribe, unsubscribe, put, get, list can be used on their own in a message as the schema requires a valid update with at least one value in the same message. I'm struggling to imagine a scenario where this makes sense.

Although not specifically mentioned in the Subscription Protocol documentation, it appears to be using subscribe.json and unsubscribe.json.

See #232 for the discussion when this was added.

@rob42 you mention that you are using get and put (at least as of Aug 2016). Is this still the case? If so can you give some examples and responses so we can get some documentation written.