Backslashes vs. slashes - who knew?

Here's something I'd never noticed until today, when I discovered it quite by accident. In general, to run a program in a different directory, you specify the path with backslashes, such as C:\WINDOWS\system32\notepad.exe. This should be no surprise. What is surprising, though, is that if you use call to run this, you can use forward slashes: call C:/WINDOWS/system32/notepad.exe.

I'd love to know the reasoning behind this; it's not particularly useful unless you're a Linux guy who can't get out of the habit of using /. Even then, though, it's exceedingly unlikely that you'd precede everything with call.