Should be added to the release notes section for each insert set. For individual (1-off) cards perhaps a Note 2. For base sets with SP and SSP, the info can be added to the set release notes.
See https://www.tcdb.com/Inserts.cfm/sid/9016/2001-02-O-Pee-Chee
~Rob~
Hockey set collector including inserts, ERR, COR, VAR. Knowledgeable about 1968-69 to 1994-95 hockey.
All 1990 and newer cards for trade are NRMT. Expect the same in return. 1989 and older are assigned a grade. Everything on my trade list is available for sale. Reasonable prices based on condition. If it's not on my tradelist, it's not available.