Your file name should end with an extension. This helps NWE computers identify the file. We have a list of common filetypes handy. Names should be specific. You can make your names long, so don't be afraid to make them descriptive.
Names can be upper and lower case, but all lower case is strongly preferred.
The computers are case sensitive. Upper and lower case letters are not interchangable in file names. Let's look at some document names and whether they are good ones. No blanks, no special characters, ends with an extension and is all lower case. Not a good name.