I don't agree with your comment:
Quote
Secondly, weak jump responses and non-forcing Stayman are not part of SAYC. You shouldn’t say you’re playing SAYC when you’re not playing SAYC!
Many people don't want to play exactly SAYC, because SAYC has some treatments that almost no one actually plays (like 1m-2NT game forcing). They use SAYC as a starting point, and then add/subtract to get a system they prefer. This is easier than listing all the conventions you play.
Or they intend this to mean "I play SAYC, but I also know these other conventions, and I'll play them as well if you want."
Back when I used to play with randoms on OKBridge, I noticed that many people put SAYC in their profile, but didn't play Jacoby 2NT (few of them actually read the SAYC booklet). So in my profile, I wrote "SAYC (including Jac2N)" as a reminder. It's not redundant if the reader doesn't realize it.