Moderator emeritus
Jan 9, 2004
Grand Rapids, MI, USA
Discussion of what characters are allowed in MacHFS+ here.

If you want a \ etc in it, you must put the file name in quotations (if you do it directly from the command line), because otherwise the \ represents the next character as special.

For instance you can enter the filename "test file" at the command line without quotations as

test\ file

This filename does not have a \ in it. But if you create a file called "test\ file" it will actually have a \ in it.


macrumors 603
Aug 15, 2001
The Cool Part of CA, USA
Anything but a colon (because the colon was the directory separator for the old MacOS). In fact, any Unicode character at all except for a colon--just about any language or special characters you can think of. I just put every non-colon punctuation mark on my keyboard into a filename (including wildcards like & or *), and nary a hiccup.

Actually, it may be technically possible to put colons in as well, but most Mac apps won't let you, anyway, I assume because it would confuse the hell out of older programs without full long filename support. The save dialogues try to prevent you from using a forward slash (/) in filenames as well, since that's the Unix directory separator, but it can certainly still be done, even in the Finder. It's just not a terribly good idea.