Who says they are "secret"? They're known by those with a need to know. Do you expect every purchase to be made public in your daily paper? Entry 478QS3, $7500: bribe paid to Uballah Qinaa for the secret location of OBL.
Entry 2239XP, $32 to Wal*Mart, 27 rolls of toilet paper for the Ladies Toilets in the Pentagon.
Entry 678RQ2, $409,000,000 to Boeing to replace 1165 drones lost to enemy fire
Entry 456ut9, $1233 paid to Goodyear for four puncture resistant, self sealing tires for Parade Limo serial 3759984h8574.
Your paper will need another hundred pages every day.