Is there a way to attach a text field to a clip instance?

I'm a developer working with a client. The client imports a single instance of a long video file (10min). He then drags that single instance to the timeline over & over, cutting it up into lots of different clipitems. I can't change his workflow.

I need a way for him to uniquely name or tag those different clipitems. The way he's working, if he renames one clipitem, they are all renamed. If he adds a marker to one of the clipitems, all the clipitems get it.

I had an idea to add an effect to a clipitem that does nothing but has a text field on it -- that way I could sneak a name onto the clipitem since effects are unique per clipitem instance. But there don't seem to be any effects that store strings. Am I wrong? Or is there another way to attach *something* to those clipitem instances that will uniquely identify them via string and pass through to a fcpxml on export?

Thanks for your help!

Raphael