diff --git a/scripts/_common.sh b/scripts/_common.sh
index 03af121..dcfb7b9 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -9,7 +9,10 @@
 #=================================================
 
 is_public_ip(){
+# used to discriminate publics IPs over private IPs
+
 	local IP="$1"
+
 	if [[ "$IP" =~ ^10.*|^169.*|^172.*|^192.168.* ]] ; then
 		# private ipv4, so false
         return 1