diff --git a/Docs/developer b/Docs/developer
index 753c6cca6..aab89b53a 100644
--- a/Docs/developer
+++ b/Docs/developer
@@ -86,6 +86,7 @@ Specifications:
 - XHTML 1.0	http://www.w3.org/TR/xhtml1/
 - CSS 2.1	http://www.w3.org/TR/CSS21/
 - HTTP/1.1	http://www.w3.org/Protocols/rfc2616/rfc2616.html
+                and errata http://purl.org/NET/http-errata
 		(see also http://www.w3.org/Protocols/)
 - HTTP Authentication	http://www.cis.ohio-state.edu/cgi-bin/rfc/rfc2617.html
 - PNG		http://www.w3.org/Graphics/PNG/