API talk:Allusers

• When using auprop=centralids, there appear three sub-objects of the objects contained in the allusers JSON array. While the meaning of centralids is clear, the meaning of attachedlocal and attachedwiki is not. I guess (from test queries) that attachedlocal somehow describes attachment of an account to the wiki where the query is made, but the fields (CentralAuth and local) are always true (if the user is not attached to the wiki where the query is executed, the user does not even appear in the list). I also guess that inside attachedwiki, CentralAuth set to true means that the account in question takes part in SUL. I am not quite sure, though, what local is supposed to mean there. From test queries I guess that it is set to true if the wiki whose id is given to auattachedwiki is the wiki where the query is executed, but I cannot really see what a use-case of that would be. So, am I right regarding the field meanings, and what is the use of local inside attachedwiki?
• Will these outputs be generated by any wiki or just by wikis with the CentralAuth extension installed? What will happen when using auprop=centralids and possibly auattachedwiki on a wiki without CentralAuth extension?

All username are capitalized, that means not any usernames start with a-z.

When you query from api parsing aufrom=a, you'll get a unexpected response. So I think it's better to tell api users that there's no usernames start with a-z at all, CLEARLY, or auto response with A-Z, just like Special:ListUsers does.