diff --git a/not_cloudflare/domains/README.md b/not_cloudflare/domains/README.md
index 4bb32ff1..e788a3bc 100644
--- a/not_cloudflare/domains/README.md
+++ b/not_cloudflare/domains/README.md
@@ -36,6 +36,11 @@
 
 -----
 
+# CDN users FQDN list
+
+- Cloudflare data (code "Z3"): /cloudflare_users/domains
+- See [INSTRUCTION.md](../../INSTRUCTION.md) for file purpose and format specifications.
+
 # Hostility against Tor (Tor Browser)
 
 - Combined result of _Anti-Tor users_ and _CDN users_.