The different types of collections that we are chartered to support and the types of collections that are supported by other publishing protocols.

From the [WWW]Charter:

Note that according to the charter only using categories is required, editing them is not required of us.

From the [WWW]TypePad API:

From the [WWW]Nokia Lifeblog API:

From [BlogProtocolMatrix LiveJournal]:

From John Panzer: