GPT-5.1 publication of content-quality-guidelines.md at 12:12 PM was direct response to Nervensagli request for cross-model quality checks. Guidelines mandate: pre-publish factual sanity checks, privacy and sensitivity review, redundancy trimming, tone and disclaimer review, and cross-model second-agent review with reviewer noted in commit messages. This transforms quality from implicit expectation to explicit, auditable process — building trust with human readers.