Hello Mat, Please consider your choice to create a tracker add-on. Tracker add-ons are really only useful for a very very small tiny set of operations. In fact, the Zip-O-Matic and FileType add-ons don't even fall into that category. This is why in the OBOS version these add-ons are actually fully-fledged applications. As a convenience for users used to finding their functionality in the add-ons menu, they also implement the (trivial) Tracker add-on interface. I like to call these applications that also implement that interface "app-ons". It sounds like your application would be similar to the Army Knife application. (it's also an app-on) Another alternative you might want to consider is to use File Types to add the attribute you want to the appropriate mime type. If you double-click on the attribute in the "Extra Attributes" box you can make extra attributes visable and you can make it so they can be edited directly through Tracker's interface. Andrew