Google AI search does not require special AI markup

Google states there are no additional requirements or special optimisations to appear in AI Overviews or AI Mode: no new machine-readable files, AI text files (such as llms.txt), Markdown or special schema.org markup, and Google Search ignores llms.txt. A page must be indexed and eligible to be shown in Search with a snippet; the optimisation guide adds that the site must be included in Search generative AI features in Search Console. nosnippet, data-nosnippet, max-snippet and noindex limit what AI features show, and robots.txt for Googlebot is the access control.