serial port pinout

Why do the serial ports have a male connector (like a PC), but do not have
pinout like PC?  You can't use a standard serial cable (DB9 straight
through extension cable) to connect to a "slave" device, or a standard null
modem adapter (cross-over with females at both ends) to connect to a PC.
Was this a mistake, or am I missing something?

didnt  you  get  a  9 pin  serial  cable in  the box when  you  bought 
your  fa?

look  at  page  6  of the 2440 schematic

looks  to  me  like   the   pinout   is  for  a  slave  device
double  check  it  please.