For years, telling AI companies not to train on your website meant a small zoo of crawler rules \u2014 Google-Extended, GPTBot, ClaudeBot, CCBot \u2014 each with its own syntax and no guarantee the next model would respect any of them.<\/p>\n
That changed on October 30, 2026, when Google, Microsoft, OpenAI and Anthropic each announced they will honour one shared AI training opt-out in robots.txt: a policy token called __usage_ai-training. One small group in your robots.txt becomes a binding instruction \u2014 as each company’s rollout lands \u2014 not to use your content to train generative AI models.<\/p>\n
Here is what happened, how the token works, where the four timelines diverge, and what to do now \u2014 whether your audience is in London, Dubai or Riyadh.<\/p>\n