The features described in this topic are obsolete
and should not be used in new IDL code.

Detecting Use of Obsolete Features

You can search for usage of obsolete routines, system variables, and syntax by setting the fields of the !WARN system variable. Setting !WARN causes IDL to print informational messages to the command log or console window when it encounters references to obsolete features. See "!WARN" (IDL Reference Guide) for details.