OK, this is something that's bugged me for a long time. I've been in the field forever, but working on Windows. So I've seen this kind of thing many times before, particularly when referencing man, and it seems completely cryptic.
The way linux people occasionally put a parenthetic number after a generic command seems to me one of the ways that normal civilians, and even pros like me, are intimidated into staying away from serious linux usage.
So what gives? What the heck is the parenthetic number for?