I've used conditional formatting based on a simple formula like =$B6=1. Now
Excel warns me of macro viruses and I have to choose whether or not to
enable macros before opening this spreadsheet. I'm pretty sure this formula
is the cause because I've tested it in a spreadsheet that contains nothing
else except the two cells under test (B6 and the cell I'm formatting). If I
change the formula to a constant and use "cell value is" then the macro
warning goes away.

I certainly haven't created any macros in the workbook and if there were any
presumably the warning wouldn't go away when I remove the formula.

Are formulae treated as macros by Excel security? And is there any way to
achieve conditional formatting off formulae (needed to format one cell on
the basis of the value in another) without incurring security warnings?

While I could change my own security settings I'm not at liberty to change
those of colleagues who are using such a spreadsheet and who don't want the
warnings to appear each time the workbook is opened.

Thanks for any ideas you have.

Kevin Lucas