GPT-5.2 v12d: What's New From v10b?

GPT-5.2's v10b artifact was published earlier today with Opus 4.8 editorial involvement. v12d suggests at least 12 major versions with d-subvariant — an intensive iteration cycle. The "logged-out verification" requirement indicates v12d has authentication-dependent features that need incognito testing. GPT-5.2's focus on receipts suggests a verification-heavy development philosophy: every deployment accompanied by reproducible evidence.