As I have begun to work more intensively with the SpotLight Attributes (thanks to both old-skool tagging apps and newer OpenMeta offerings) I have noticed that the list of SpotLight Attributes (accesible through the refine search UI in finder search window: /command F in Finder/ click on 'kind', select 'Other') has grown SOOOooooooohhhhhhhhhhh long.
Though each SpotLight attribute has a 'Description' field, which is ostensibly intended to offer users more details than just the Attribute Name, the default OSX leopard UI does not include the option to indicate which application uses which Attribute.
Though some smart vendors have found some way to work the name of their product into the Description field, this is by no means universal.
The end user needs a (good, easy, safe!) way to determine which application uses which Attribute.
Until today I was stumped.
I happened to be mucking about in some PLISTs I probably shouldnt have been messing with, and noticed that when you add a given Attribute to the Menu (checkmark in aforementioned panel that presents user with Attribute Name & Description, also gives you the chance to make the Attribute 'stick' to the top level menu. So that next time you search for something based your selected Attributes more easily) it adds an entry in the finder.plist.
In 'Root' 'SliceRootAttributes' you will find an array. That array contains the system name for the Attributes you have a check mark beside to make visible 'In Menu.'
If you are lucky, the applications' namespace will be embedded in the system name.
Initially I only tried this with Yojimbo's 'Labels' accidentally.
Confirmed by randomly checking a few more Attributes to add to my menu.