There are two functions that come with SAP Business Objects Crystal Reports that can help you display on your reports when the report format was last modified.  These functions are found under Functions>Document Properties and are labeled ModificationDate and ModificationTime. 

For use, I created a new formula called ModificationDateTime and added the following syntax:

"This Report Format Last Modified on "+Cstr(ModificationDate)+" at "+Cstr(ModificationTime)

I put my formula field in light gray letters in the page footer, light enough for someone to just barely see it. 

This way when you get complaints about one users report does not look like another users version of the same report you can peek at the ModificationDate/Time displayed on the bottom and tell them they have an outdated report. 

If you play around with some of the functions in the Functions>Document Properties of the tree, you will find several functions that could come in handy.  I will show you some of those in the next few days.

Have a great weekend!

Geo