Ask HN: What's your personal standard for filenames?

Here's mine, rule : reason no whitespace : don't need to escape whitespace when using a shell all lowercase : easier to type, easier to read a directory listing, exceptions for filenames which should begin with an uppercase according to another formal specification, such as Java class names alphanumeric : [A-Za-z0-9] printable, typeable begin with a letter : easier to read a directory listing word separator is '-' : looks nicer than '_', exceptions for when the filename is a symbol in a programming language such as '_' for Python modules