How do formula functions respond to capitalization? Is there a guide to this?

Well, I'm honored to have Mark And Dan sniping at each other on my question. I guess my constant work with reports sets my expectations for formula functions. I probably use 'contains' or 'begins' most of the time, so that probably reduces the likelihood of this problem, as well. 

And as to keystrokes, I hate using lower or upper functions altogether for that exact reason. I hate any extra parentheses in general, besides the need for four key strokes, they are the reason most of my formulas don't work the first time.

Thanks for your help, guys!