Does INCV actually do anything?

[sgqwonkian]

According to the Modmakers Guide to the Galaxy, there's a code for PAGE blocks called INCV:

"INCV <variable> <number>
Increments a user variable by an integer (or subtracts if the number is negative)."

It sounds like a really useful bit of code for my upcoming Odyssey-based mod and my upcoming Cthulhu-based mod.

But I can't seem to make it work. Or at least events that say "INCV crewnumb 40" seem to have no impact on a item with "TEXT Your ship has <uvar=crewnumb> crewmen on board."

I've searched the files of the main game trying to find an example of how to use it, and _if_ there's INCV code in action, and it's not in the mission, game, damocles quest, kawangi quest, or any of the dv_whatever items. And I'm pretty sure it's not hidden in any of the normal see-them-almost-every-game quests.

Does INCV actually do anything?
Does it really exist?
Does it only work if you're running the 1.22 patch?

Has anyone had any luck using the INCV code?