citation to http

diff --git a/harmful/software/http.md b/harmful/software/http.md
index 80f172d..1f3b796 100644 (file)
--- a/harmful/software/http.md
+++ b/harmful/software/http.md
@@ -1,6 +1,8 @@
 # HTTP considered harmful
 
-HTTP is spyware by design, why was User-Agent necessary?
+HTTP is [spyware by
+design](https://tools.ietf.org/html/rfc2616#section-14.43), why was
+User-Agent necessary?
 
 User-Agent can by easily faked, but I don't think it was 100%
 necessary.