diff --git a/docs/Channel-Variables-Catalog/EXTEN_16353770.mdx b/docs/Channel-Variables-Catalog/EXTEN_16353770.mdx
index d88825bb..ece8eac9 100644
--- a/docs/Channel-Variables-Catalog/EXTEN_16353770.mdx
+++ b/docs/Channel-Variables-Catalog/EXTEN_16353770.mdx
@@ -5,6 +5,6 @@
 
 ## EXTEN
 
-string
+string, equals to the destination number, used with [mod_dialplan_asterisk](https://developer.signalwire.com/freeswitch/FreeSWITCH-Explained/Modules/mod_dialplan_asterisk_3966416/)