Classes
A class is who a group-scoped event is about. A static class keeps a list you add to; a dynamic class holds whoever's attributes contain its filter, so nobody keeps it up. Beside the classes somebody keeps are temporary lists, picked by a person for one send: you can see them, but a key cannot change one and an event cannot name one. In the High school pack a class is, for example, “5A”.
DELETETake someone out of a class
Requires groups:write. Named by Raven's id for the student or parent, not by a membership id. Membership is who is in the class now, so this really removes; what was sent to them while they were in it is untouched. The one DELETE in the API.
204 with no body. 404 when they are not in this class. 409 on a temporary list.
None: success is 204. On failure the body is { error, code }.