What are the Legal / Allowed characters for web server file names on?

Question

What characters are allowed in filenames for HTML files on ALL servers (*nix, Windows, etc.) ? I'm looking for the "lowest common denominator" that will work on all servers. USE: I'm naming a file to be served up publicly (Mysite.com/My-Page.htm)

E.g., space? _ - , etc.

E.g., can I have File-Name.htm, File_Name.htm File Name.htm?

Obviously, this needs to work with all servers and browsers. (IIRC, the name is limited by the server not the browser, but I could be wrong).

Answer 1

If you don't want your filenames to be encoded by the server, you should avoid reserved characters: $&+,/:;=?@ and unsafe characters: space, quotation marks, <>#%{}|\^~[]`

But as the previous answers stated, the web servers should cope with whatever you want to use by encoding the chars.

Answer 2

I would say a good rule of thumb for filenames for HTML files on ALL servers can be any combination of alphabet (lowercase preferred) and number characters (1 though 9), plus the underline(_), minus(-) or plus(+) characters but no spaces. Also, end the filename with dot html (e.g. filename.html). I personally avoid using underline and plus characters.