Lacking specification of rules of HTTP methods for Description Resource

Issue Content

I'm finding some use cases for the Description Resource (DR), but found that the way how they can be manipulated is not made clear in the spec. In particular, the following questions are unanswered (assuming permission is met):

0. (Prerequisite of the rest) Is the user allowed to modify the DR?
1. What HTTP requests are supported for a DR?
   • I presume OPTIONS, GET, POST, PUT and PATCH are all supported in the same way as a normal resource when the DR exists?
2. Can I send a DELETE request to the DR, and what would happen?
3. If, for some reason, there is no DR for a resource yet (but server has capacity), how can I create a DR?
4. Am I allowed to associate a different DR with the resource on a custom location?

Also, this sentence is not clear enough:

Servers MUST NOT directly associate more than one description resource to a subject resource.

Does this mean the server can indirectly associate more than one DR to a subject resource? If so, how?
Or, does this mean the user (rather than the server) can associate more than one DR?

Generalization

Actually, this question can be generalized to all Auxiliary Resources (AR): what ARs can be modified by the users, and are they subject to the same mechanism?

Related topics

• #521: It concerns all types of AR, especially ACL; it assumes DR are managed by server (thus not modifiable by user); it also does not discuss modifications.
• #184: It concerns all types of AR as well, in terms of recursive AR (i.e. AR of AR); it also touched a bit on the ACL and use cases of recursive AR.
• #362: It discusses the possibility to use DR to store container's metadata (managed by server?); it is more a use case for DR rather than protocol for interacting with DR.
• #177: It talks about server-managed resources, and assumes all AR belong to this category. However, since ACL is modifiable by users, some differences must exist in AR.
• Maybe some other issues with label "topic: auxiliary resources", but I don't see any more for now

Start with the auxiliary-resources Description Resource section of the Solid protocol specification and review related issues #521, #184, #362, and #177. Determine where the specification needs clarification for HTTP methods, user modification, association, and the broader Auxiliary Resource question; done means the applicable rules and terminology are explicitly documented.