There are 3 lips that get confused. There's the replica of the OEM Optional ITR lip for both the 94-97 front bumper and the 98+ front bumper. There is also a lip marketed often as an ITR lip, but its actually a CTR (Civic Type R) lip, which also fits on an integra.
This is the lip marketed often as an ITR lip, but its actually a CTR (Civic Type R) lip: