Merge pull request #13480 from ArcticSnowman/master

Update to ldap.md

docs/sources/auth/ldap.md

@@ -181,6 +181,7 @@ group_search_filter = "(member:1.2.840.113556.1.4.1941:=CN=%s,[user container/OU
 group_search_filter = "(|(member:1.2.840.113556.1.4.1941:=CN=%s,[user container/OU])(member:1.2.840.113556.1.4.1941:=CN=%s,[another user container/OU]))"
 group_search_filter = "(|(member:1.2.840.113556.1.4.1941:=CN=%s,[user container/OU])(member:1.2.840.113556.1.4.1941:=CN=%s,[another user container/OU]))"
 group_search_filter_user_attribute = "cn"
 group_search_filter_user_attribute = "cn"
 ```
 ```
+For more information on AD searches see [Microsoft's Search Filter Syntax](https://docs.microsoft.com/en-us/windows/desktop/adsi/search-filter-syntax) documentation.
 
 
 For troubleshooting, by changing `member_of` in `[servers.attributes]` to "dn" it will show you more accurate group memberships when [debug is enabled](#troubleshooting).
 For troubleshooting, by changing `member_of` in `[servers.attributes]` to "dn" it will show you more accurate group memberships when [debug is enabled](#troubleshooting).