[Faryn]

Thanks, Sab, but that info (as you say) is for the reverse of my problem. I need to find a way to impose the collection data onto the tags. I assume that there's a way, I just don't know how. Otherwise, I'm resigned to entering the tag data one book at a time.

I even tried deleting a book from the library, and copying it over from the ereader. No luck; the collection info didn't transfer over to the tag. Unfortunately, the file, when copied from the ereader to calibre on my pc, did seem to have the tags on them. Ugh.

I did go and clear all of the tags on the pc. That was easy, because calibre allows me to do that en masse through "edit metadata in bulk". Once I find out how to impose the collections in one fell swoop, I can sort out future additions myself by simply editing the tags to match the appropriate ereader collection.