Why it matters
Content-Signal (search, ai-input, ai-train), from Cloudflare and aligned with the IETF AIPREF draft, states how content may be used beyond crawl permission. It's an emerging, non-binding signal.
How to fix it
Optionally add a Content-Signal line to the robots.txt group(s) it applies to.
Example
User-Agent: *
Content-Signal: search=yes, ai-input=yes, ai-train=no
Allow: /References
More ai search rules
void geo reports 41 rules in this category. Generative-engine optimisation: whether AI crawlers that don't run JavaScript see the same content, valid and visible JSON-LD, an explicit AI robots policy, llms.txt, Markdown mirrors and answer-first writing.
llms-txt-missingNo /llms.txtllms-txt-error/llms.txt returns a server errorllms-txt-invalid/llms.txt doesn't follow the llms.txt formatllms-txt-broken-links/llms.txt links to URLs that failllms-txt-not-linkedllms.txt exists but isn't linked from the home pagerobots-ai-policyAI crawler policy (allow/deny matrix from robots.txt)search-bots-blockedrobots.txt blocks AI search or user-triggered fetcherstraining-bots-blockedrobots.txt blocks AI training crawlers