---
type: Glossary Term
title: "Content-Signal directive"
description: "Content-Signal is a machine-readable policy directive introduced by Cloudflare's Content Signals Policy that publishers place in robots.txt or HTTP response headers (Content-Signal: search=yes, ai-input=yes, ai-train=no) to express separate permissions for search indexing (search), live RAG/grounding retrieval (ai-input), and foundation model training (ai-train)."
resource: "https://agenticweb.wiki/terms/content-signal/"
tags: ["glossary", "permit"]
status: stable
generated: { by: agenticweb-builder/1.0, at: 2026-10-23T00:00:00Z }
verified: { by: process:agenticweb-engine, at: 2026-10-23T00:00:00Z }
stale_after: 2026-11-22T00:00:00Z
sources:
  - id: ref-1
    resource: "https://blog.cloudflare.com/content-signals-policy/"
    last_modified: 2026-09-05T00:00:00Z
  - id: ref-2
    resource: "https://developers.cloudflare.com/bots/additional-configurations/managed-robots-txt/"
    last_modified: 2026-09-05T00:00:00Z
---

# Content-Signal directive

**`Content-Signal`** is a machine-readable policy directive introduced by Cloudflare's Content Signals Policy that publishers place in `robots.txt` or HTTP response headers (`Content-Signal: search=yes, ai-input=yes, ai-train=no`) to express separate permissions for search indexing (`search`), live RAG/grounding retrieval (`ai-input`), and foundation model training (`ai-train`). It complements per-bot `User-agent` rules (`GPTBot`, `ClaudeBot`, `OAI-SearchBot`) and aligns with the IETF AIPREF vocabulary effort. Used by: cloudflare-content-signals-policy, ai-crawler-tokens-robots.

# Knowledge Graph

* **Related standards**: [Content Signals Policy](/okf/protocols/cloudflare-content-signals-policy.md), [AI Crawler User-Agent Tokens in robots.txt](/okf/protocols/ai-crawler-tokens-robots.md)

[^ref-1]: https://blog.cloudflare.com/content-signals-policy/ (https://blog.cloudflare.com/content-signals-policy/)
[^ref-2]: https://developers.cloudflare.com/bots/additional-configurations/managed-robots-txt/ (https://developers.cloudflare.com/bots/additional-configurations/managed-robots-txt/)