---
title: "No Content-Signal usage preferences (geo/content-signal)"
description: "geo/content-signal: Content-Signal (search, ai-input, ai-train), from Cloudflare and aligned with the IETF AIPREF draft, states how content may be used…"
canonical: https://void-design.vercel.app/rules/geo/content-signal
lastModified: 2026-09-16
---

# No Content-Signal usage preferences

`geo/content-signal` · severity **info** · category AI search · detected by `void geo` and `void audit`

## 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

```text
User-Agent: *
Content-Signal: search=yes, ai-input=yes, ai-train=no
Allow: /
```

## References

- https://contentsignals.org/
- https://datatracker.ietf.org/doc/draft-ietf-aipref-vocab/

## 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-missing` No /llms.txt — [geo/llms-txt-missing](https://void-design.vercel.app/rules/geo/llms-txt-missing)
- `llms-txt-error` /llms.txt returns a server error — [geo/llms-txt-error](https://void-design.vercel.app/rules/geo/llms-txt-error)
- `llms-txt-invalid` /llms.txt doesn't follow the llms.txt format — [geo/llms-txt-invalid](https://void-design.vercel.app/rules/geo/llms-txt-invalid)
- `llms-txt-broken-links` /llms.txt links to URLs that fail — [geo/llms-txt-broken-links](https://void-design.vercel.app/rules/geo/llms-txt-broken-links)
- `llms-txt-not-linked` llms.txt exists but isn't linked from the home page — [geo/llms-txt-not-linked](https://void-design.vercel.app/rules/geo/llms-txt-not-linked)
- `robots-ai-policy` AI crawler policy (allow/deny matrix from robots.txt) — [geo/robots-ai-policy](https://void-design.vercel.app/rules/geo/robots-ai-policy)
- `search-bots-blocked` robots.txt blocks AI search or user-triggered fetchers — [geo/search-bots-blocked](https://void-design.vercel.app/rules/geo/search-bots-blocked)
- `training-bots-blocked` robots.txt blocks AI training crawlers — [geo/training-bots-blocked](https://void-design.vercel.app/rules/geo/training-bots-blocked)

Detected by `void geo` and `void audit`. Explain it in a terminal: `void rules geo/content-signal`