I wanted to pull a few of checklist items from #1197 that related to ?include/included out into a separate thread, since that one was getting pretty crowded and these questions seemed severable. The result of this discussion can then be used to update the checklist in #1197. In particular, this issue is for the items:

• Should sideposted resources [in the request document] be within the included member or within some new ad-hoc member?
• Should created sideposted resources in the response be within the included member or within some other ad-hoc member?
• What should happen if a client uses ?include on their POST and (for some reason) doesn't list in that param all the relationship paths for which they sideposted resources?

My current thinking on this is:

• Sideposted resources should go in included, in both the request and response documents. What are the arguments against this at this point? I know I initially used a member called embedded but I'm not sure that ever really made sense.

• Any sideposted resources should always be included in the response regardless of the value of the ?include parameter. Letting the ?include parameter exclude newly sideposted resources just seems to add way more complexity than it's worth. (See discussion here.)