C langauge question

int
add(a, b)
  int a;
  int b;
{
}

Rookie question. What's the benefits of this type of declaration? Also, are there any books that teach this indent style? The GNU C Library seems to make use of it. And so does Julian Assange:
http://ftp.cerias.purdue.edu/pub/tools/unix/scanners/strobe/strobe/strobe.c

>>7
    int
    add
                  (
           a,   b
      )
       int a,
            int b;
                  {
     return a + b;
    }
Updated for expert turkey compliance.