COTag documentation
COTagLibrary : COLibraryOverview
A tag library content is restricted to COTag objects.
To access and change the library tags, use COCollection API. For example, -content returns all the tags in the libary.
For organizing tags, see -tagGroups .
Although multiple tag libraries can be created, it is usual to use a single library per CoreObject store. See -[COEditingContext tagLibrary] .