Thanks, Gregg and JE. As I thought about it over the weekend the
solution I came up with was to set a boolean value to FALSE on file
exit, and use a startup macro to set that value to TRUE when they
accepted macros. Then tag certain critical formulas to operate only
when that value is TRUE. But I like the xlVeryHidden idea- thanks.

Is there- or did there use to be- a function called xlHopelesslyHidden?
This is ringing a bell for some reason.