Thread: Cant Understand the syntax

I've seen the following in a .c File

Code:

static void MDString PROTO_LIST ((char *));
static void MDTimeTrial PROTO_LIST ((void));
static void MDTestSuite PROTO_LIST ((void));
static void MDFile PROTO_LIST ((char *));
static void MDFilter PROTO_LIST ((void));
static void MDPrint PROTO_LIST ((unsigned char [16]));

But cant understand what does it mean.
PROTO_LIST is a function or a struct name.
But still the syntax is complex to me I cant understand it.
anyone plese clearify.