libnet_build_tcp_options() help needed

Hi 

Could someone please explain to me what those numbers means in the following line. ( first argument )

t = libnet_build_tcp_options( 
"\003\003\\012\001\002\004\001\011\010\012\077\077\077\077\000\000\000\000\000\000", 
20, 
l, 
0); 

My guess is that they are the different tcp options like max tcp payload, window scale factor etc, but I have no idea about the mapping between the names and these numbers.
Eg : 000 - NOOP 
001 - Some TCP option 
etc etc 

Thank you
psynaps3