The_Rookie wrote ... the "Skylar Diggins" headband ... For enforcement, do you have players remove the whole thing or just ask them to tuck in the tails and play on?

Skylar Diggins (Notre Dame 2009-2013, WNBA 2013-Present), as an All-American point guard for the Notre Dame Fighting Irish popularized knotted headbands with long loose ends. In 2015, the NFHS ruled that headbands must be without extensions.
I would prefer to tell them they can't play with the "Skylar Diggins" headband, but that doesn't appear to be the standard operating procedure here in my little corner of Connecticut, so I would stick out like a sore thumb (Overly Officious Official) if I did, so I just reluctantly tell them to tuck in the tails.
The usual caveat, check your local listings.