Actually, CAL was a macro but I'm trying to localize it
Did you remove all the CAL macro definitions? maybe there was more than one and you missed it?
An easy way to test this would be to do this just before line 550:
1 2 3
#ifdef CAL
#error "There is a lingering CAL macro somewhere"
#endif
If you get the error, then you missed a macro.
Is there anything else it could be?
There's always the possibility, but in this case I really don't think so. If there's no macro, then there's nothing wrong with line 550 and it should be compiling OK.
If it was some other kind of name conflict the error woud be different... but the error you're getting suggests the macro is replacing CAL with garbage.