@Davidbrian
Are you referring to a I-175 Border crossing card issued by INS? Those were not supposed to work any longer, everyone was put back on the waiver program.
If you were issued something prior to 9/11, be aware that they might just deny you entry without a valid recent waiver. I had a client issued a "September Letter" in 1997 but he had 2 convictions. I was shocked he got the September Letter, but good for him. The letter was issued by INS in Buffalo.
Right before covid, he booked a $5000 vacation with the wife to Hawaii. The officer at Pearson looked at the letter, then looked at his record. They eventually denied him entry, kept the letter, and he was so bitter, he started a waiver but refuses to finish it. His wife was very upset, but he couldn't get past the "its unfair" stage.
Anyways, when I followed up, his wife had left him, and he was literally not over how "unfair" this all was. I explained, but you got a September Letter probably by fluke so you didn't have to do a waiver for YEARS. He didn't care. So he lost the money, the trip and eventually his wife.