What is the type of an enum whose values appear to be strings?

Question

I am working with Apple\'s ScriptingBridge framework, and have generated a header file for iTunes that contains several enums like this:

Answer 1

That is an Apple extension to C, which It basically translates those enums to:

typedef enum {
    iTunesESrcLibrary = 'k'<<24 | 'L'<<16 | 'i'<<8 | 'b',
 ...
 }

EDIT: Sorry, apparently it's valid C. I've only seem them in Mac code, so wrongly assumed that it was Apple specific.