As far as I can remember 2007 version supported 64 nested IF which seemed to be far more than someone could try to write, and sincerely in 2010 version I didn't checked it... but I guess that this number would be enough for you. If not, I want to see that formula right now.
could you explain what you're trying to accomplish? perhaps theres and easier/better/faster way.
and just to answer your question: you can nest basicaly any fucntions together as long as the nested function(s) return the correct type of data for main functions arguments.
Sorry I didn't understand at a first glance. Regarding your formula, in which you can nest OR & AND functions as needed, it's doing this:
- when F2="Stewart" and BJ2<>"MFC" and BN2="#N/A"... wait!
BN2 is being tested against a string constant "#N/A" and not against a not available error value which displays as #N/A. If this is the case replace the BN2 test with ISNA(BN2) criteria.