I have a restful service where one of the collections is limited (for UX reasons). In this case it has a cap of 25 items. If that is exceeded resources must be deleted before more can be added. As an example if a client submits:
POST http://somesite.com/api/v2/stuff
{"cool":"stuff"}
and there are < 25 things in stuff:
200 OK
if > 25 things in stuff:
???
DELETE http://somesite.com/api/v2/stuff/:id
POST http://somesite.com/api/v2/stuff
{"cool":"stuff"}
200 OK
What is the best code for this? Straight 400? 409 CONFLICT? 429? None seem quite right..