Draft standards for content-use preferences

The IETF AIPREF working group's two drafts are still Internet-Drafts, not RFCs: draft-ietf-aipref-vocab-08 (13 September 2026) defines three usage categories, train-ai (training a generative model), ai-use (using the asset as input to a generative model when the user did not supply it) and search (selecting assets and directing users to them, with links and excerpts), each set to y or n, where any n wins over a y; draft-ietf-aipref-attach-05 (18 August 2026) attaches them through a Content-Usage HTTP header and a Content-Usage rule in robots.txt (for example Content-Usage: train-ai=n). Its labels differ from Cloudflare's Content-Signal (ai-train, ai-input, search).