How to change error message containing "Unexpected Error"

I'm familiar with using the cferror template, but I haven't see how to edit this particular line of text that reads, at the very top of any ColdFusion error:
"The web site you are accessing has experienced an unexpected error. Please contact the website administrator."

For one thing, sometimes the error IS expected, and the way this is worded sounds like it is the fault of the programmer. Bleah!

Possible to edit/change? I looked in the classic.cfm debug template but don't find it there. Maybe compiled into the java debugger? If so... boo!

Thanks for any suggestions.

Chuck