You should not use pound (#), percent (%), ampersand (&), left bracket or right bracket ({}), backslash (\), left angle bracket or right angle bracket (<>), asterisk (*), question mark, forward slash (/), blank spaces, dollar sign, exclamation point, single quotes or double quotes (',"), colon (:), and the at sign (@)
you probably also shouldn't start, or end your file name with a space, period, hyphen or underline, and since most operating systems are case sensitive you should use lowercase letters.
avoid using spaces or underscores.