I just had a co-worker sigh and gripe out loud because I had filed a file under the last name. Even though the first name is part of the business name, I find it much easier to look under the last name. If we filed under "Jack" for example, there could be several Jacks. What is acceptable? (In this case the drawer was not that large and it was logical to look under the last name if it wasn't under the first - but she tends to make a "big deal" out of things). That makes me want to sigh...

Different people use different filing systems.
You need to find a common ground and standardise on that.