Microsoft sets 1 February 2027 to honour a shared AI-training preference, and adds a grounding control

Microsoft's Bing blog, dated 30 October 2026, says it will offer publishers separate preferences for AI training and for grounding, and that those preferences do not change eligibility for traditional Bing search results. The post says they do not establish licensing or payment arrangements. It says the training preference is the shared one being discussed in the IETF AI Preferences working group and described in an Internet-Draft. The examples use the robots.txt token __usage_ai-training. OpenAI and Google also posted on 30 October about that shared training signal. This post is Microsoft's schedule and its separate grounding control.

The post says AI Training can be set in robots.txt for a site or path, and also at page level, where a page setting overrides robots.txt. AI Grounding is page-level only. DisallowExtended limits grounding to Microsoft-operated experiences such as AI Mode, AI Overview, Copilot and Microsoft 365, and excludes grounding services Microsoft provides to third parties, such as Web IQ and grounding through API access in Foundry. Disallow means the content is not used to help inform generated responses. Both training and grounding default to Allow when no preference is published. The post says choosing DisallowExtended or Disallow for grounding will significantly reduce a site's visibility in AI-generated experiences.

Microsoft says it will honour the new preferences as it crawls, starting on 1 February 2027. Sites that use the existing NoArchive or NoCache tags are told to publish the new preferences before 1 March 2027. After that date, Microsoft says those two tags will no longer be read as a preference for training or grounding. From 15 December 2026, a temporary grounding transition preference opens in Bing Webmaster Tools, and the post says that option is only for sites using NoArchive or NoCache as of that date. For each page, the temporary preference applies until Microsoft recrawls the page or until 30 September 2027, whichever is earlier. The post says that if a site does not record a temporary grounding preference by 1 March 2027, pages that use NoArchive or NoCache default to Allow for grounding until Microsoft recrawls them and finds a new grounding preference.

What it means for business: nothing in this post is a statute. A site that already blocks training with NoArchive or NoCache is told those tags stop working for training and grounding after 1 March 2027, and that the new preferences take effect as Microsoft crawls from 1 February 2027. Search eligibility is described as unchanged. The post does not say the new tags create a payment or a licence.