As long as your file names meet operating system requirements, you can use whatever you like; the rest is up to you
A customer had a question about the MSDN documentation on rules for legal file names:
My employees keep naming documents with hyphens in the name. For example, they might name a file
Budget-2012-Final.xlsx. It is my position that hyphens should not be used in this way, and the document should be named
Budget 2012 Final.xlsx. Please advise on the use of hyphens within file names.
Hyphens inside file names are legal, and you can use as many as you like, subject to the other rules for file names.
If you are having an argument with your employees about file naming conventions, that’s something you just need to work out among yourselves. Whatever you decide, the file system will be there for you.