'#include' slash error

Hi,
I was adding an ‘#include’ and by default it was inserting a backward slash. Then an error popped up saying to use forward slashes instead.

Question is: why is so important to use forward slashes?

Compatibility. And since UE4 was meant for many platforms, it’s important. Linux and OS X use forward slashes.

“…, although any compiler might choose to support a backslash in a #include path, it is unlikely that any compiler vendor won’t support forward slash”