Inconsistent description of "postmaster.opts"

--- Sample output ---
$/bin/data#more postmaster.opts
*/bin/postgres -D data
$/bin/data#cd ..
$/bin#pg_ctl -Ddata start
postmaster starting
$/bin#LOG:  database system was shut down at 2005-10-27 03:17:17 EDT
LOG:  checkpoint record is at 0/33AE4C
LOG:  redo record is at 0/33AE4C; undo record is at 0/0; shutdown TRUE
LOG:  next transaction ID: 570; next OID: 16385
LOG:  next MultiXactId: 1; next MultiXactOffset: 0
LOG:  database system is ready
LOG:  transaction ID wrap limit is 2147484146, limited by database 
"postgres"a
$/bin#pg_ctl -Ddata stop
waiting for postmaster to shut down...LOG:  received smart shutdown request
LOG:  shutting down
.LOG:  database system is shut down
 done
postmaster stopped
$/bin#cd data
$/bin/data#more postmaster.opts
*/bin/postgres -D data
$/bin/data#

--- PG manual ---
http://www.postgresql.org/docs/8.0/static/storage.html
postmaster.opts | A file recording the command-line options the postmaster 
was last started with

So two inconsistences:
(1) not necessarily postmaster;
(2) if I starup postmaster by pg_ctl, then the information is not recorded
here.

Am I misunderstand something obviously?

Regards,
Qingqing