Prevent special chars from being entered in IFS fields

Is there a way to prevent special chars from being entered into IFS fields by users? For example, percent sign %, ampersand &, underscore _, etc.

I seem to remember there being a basic data / system setup screen in IFS whereby you can list characters which you want to be “disallowed”, but I don't remember the name of the screen that holds this system setup/ basic data setting, and haven't been able to find reference to it in the help system.

Thanks in advance,