---
title: "What Content-Signals changes | Agent Ready Crawlers"
description: "What Content-Signals changes: the search, ai-input and ai-train lines in robots.txt, Cloudflare's defaults and why they enforce nothing."
canonical: https://agentreadycrawlers.com/guides/what-content-signals-change
site: "Agent Ready Crawlers"
last_updated: 2026-11-04
date: 2026-11-04
section: "Guides"
---

# What Content-Signals changes | Agent Ready Crawlers

> What Content-Signals changes: the search, ai-input and ai-train lines in robots.txt, Cloudflare's defaults and why they enforce nothing.

Source: https://agentreadycrawlers.com/guides/what-content-signals-change
Site: Agent Ready Crawlers
Last reviewed: 2026-11-04

# What Content-Signals changes

In short

Content-Signal lines in robots.txt state search, ai-input and ai-train preferences; they express a preference and enforce nothing. The Content Signals Policy defines three signals: search, ai-input and ai-train, written as comma-delimited yes or no values. Example from Cloudflare: Content-Signal: search=yes, ai-train=no under User-Agent: \*. Google intends to support the AIPREF training signal written as user-agent: \_\_usage\_ai-training in early 2027.

Content-Signal lines add a vocabulary for what a site allows after it has been crawled. They state a preference and enforce nothing.

## In practice

1.  Know the three signals: search, ai-input and ai-train, written as comma-delimited yes or no values. Cloudflare's example is `Content-Signal: search=yes, ai-train=no` under `User-Agent: *`.
2.  Expect defaults to differ. Cloudflare updated managed robots.txt for over 3.8 million domains to serve search=yes and ai-train=no, and serves no ai-input value for them.
3.  Do not treat the line as a block. Cloudflare says a robots.txt directive cannot identify who is crawling or stop a crawler that ignores it.
4.  Watch the next vocabulary. Google intends to support the AIPREF training signal, written as `user-agent: __usage_ai-training`, in early 2027.
5.  Add the line with the [robots.txt builder](https://agentreadycrawlers.com/robots-builder/) if you want it; it sets the three values from your choices.

## What the sources say

-   Primary source The Content Signals Policy defines three signals: search, ai-input and ai-train, written as comma-delimited yes or no values. [Source](https://blog.cloudflare.com/content-signals-policy/), read 2026-11-04.
-   Primary source Example from Cloudflare: Content-Signal: search=yes, ai-train=no under User-Agent: \*. [Source](https://blog.cloudflare.com/content-signals-policy/), read 2026-11-04.
-   Primary source Cloudflare updated managed robots.txt for over 3.8 million domains to serve search=yes, ai-train=no, and serves no ai-input value for them. [Source](https://blog.cloudflare.com/content-signals-policy/), read 2026-11-04.
-   Primary source Cloudflare says a robots.txt directive cannot identify who is crawling or stop a crawler that ignores it. [Source](https://blog.cloudflare.com/accountable-mixed-use-ai-crawlers/), read 2026-11-04.
-   Primary source Google intends to support the AIPREF training signal written as user-agent: \_\_usage\_ai-training in early 2027. [Source](https://developers.google.com/search/docs/crawling-indexing/google-common-crawlers), read 2026-11-04.

## Related

-   [robots.txt builder](https://agentreadycrawlers.com/robots-builder/)
-   [Content-Signal](https://agentreadycrawlers.com/glossary/content-signal/)
-   [ai-input](https://agentreadycrawlers.com/glossary/ai-input/)
-   [AIPREF training signal](https://agentreadycrawlers.com/glossary/aipref-training-signal/)

## Sources

-   [Giving users choice with Cloudflare's new Content Signals Policy](https://blog.cloudflare.com/content-signals-policy/) read 2026-11-04
-   [Have it both ways: stay discoverable in search while disallowing AI training](https://blog.cloudflare.com/accountable-mixed-use-ai-crawlers/) read 2026-11-04
-   [Google common crawlers](https://developers.google.com/search/docs/crawling-indexing/google-common-crawlers) read 2026-11-04

Last reviewed 2026-11-04