^ that summarizes my position on this issue. In the context it was suggested, $iscmd is more useful than a $cmdprefix. Though I could see edge cases where the latter might be useful too, those users/cases could still manage with $readini.
@Wims, PS. I do believe in people scripting things when they can-- but I'd like to think "is scriptable" implies "is reliably scriptable" in a non error-prone manner. As we've seen, it's not that simple to get $iscmd right on your own, there are a few cases even knowledgeable scripters can miss. Yes, it's easily scriptable, but scripting it is not obvious. IMO that makes it an exception (I also make exceptions for things that are *too complex* to script, btw, but we've rarely seen those cases, so you've never seen me suggest it :)).