diff --git a/modules/sshd-dns.mod b/modules/sshd-dns.mod
index b51368e..72c77f3 100644
--- a/modules/sshd-dns.mod
+++ b/modules/sshd-dns.mod
@@ -1,4 +1,5 @@
 #!/bin/bash
+# https://superuser.com/questions/1774154/how-to-match-a-subdomain-name-of-a-client-and-not-just-ip-of-that-client-with-ss/1851219#1851219
 
 sshd_dns () {