diff --git a/README.md b/README.md
index dd84a16..badd23b 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@ Many visitors will find these files from this repository most useful:
 - `robots.txt`
 - `.htaccess`
 
-The first one tells search engine and AI crawlers which parts of your website should be scanned or avoided. The webpages of your server are returned anyway, but the crawler "pledges" not to use them. By default, the provided `robots.txt` tells every AI crawler not to scan any page in your website. This is not bulletproof, as an evil crawler could simply ignore the `robots.txt` content.
+`robots.txt` implements the Robots Exclusion Protocol ([RFC 9309](https://www.rfc-editor.org/rfc/rfc9309.html)).
 
 The second one tells your own webserver to return an error page when one of the listed AI crawlers tries to request a page from your website. A `.htaccess` file does not work on every webserver, but works correctly on most common and cheap shared hosting providers. The majority of AI crawlers set a "User Agent" string in every request they send, by which they are identifiable: this string is used to filter the request. Instead of simply hoping the crawler pledges to respect our intention, this solution actively sends back a bad webpage (an error or an empty page). Note that this solution isn't bulletproof either, as anyone can fake the sent User Agent.