iTunes misfeature (not reported)

Today I picked up a couple of CDs in the second-hand store to backfill some music I'd borrowed off others and liked sufficiently to merit a purchase. For both CDs, iTunes informed me that importing them would clash with some existing music; would I care to replace the clashing titles? Indeed I would, this being sort of the point of the exercise.

iTunes then proceeded to populate the relevant directory with a full duplicate of the CDs ripped.

Apparently it means "replace the iTunes listing for" as opposed to "overwrite the existing file".