Various Cheats:
While holding left shift push "-" (num pad) then leave them. After that type:
savegame - saves game during missions
endmission - ends mission
topography - ?????
campaign - while in main menu (all missions)
iwillbetheone - Invincibility

Invincibility (Demo Only):
Start your mission and go until you get to the helicopter. Wait a few seconds and jump out of the helicopter. Jump out before they start screaming about the helicopter getting hit. You will become invincible until you go to the Target area and finish the level.

Full Ammo:
On the second level on campaign mode when your officer shouts go go go! Immediately type in moreammo and u will get full ammo.

Unlimited Ammo (Hex Method):
BACKUP FILES BEFORE PROCEEDING

To alter the amount of ammo available to each weapon or magazine simply edit the weapons.cfg file found in the 'saved' folder contained within your user folder.

...\Users\NAME\Saved\Campaigns\1985\

or

...\Users\NAME\Saved\Missions\01TakeTheCar\

* Save a back-up copy prior to changing !!!

The weapons.cfg file defines weapon classes
where u can change the ammo amounts.

class Magazine3
{
type="M16";
ammo=30.000000;
reload=0.133733;
id=352.000000;
};
class Magazine4
{
type="HandGrenade";
ammo=1.000000;
reload=1.215374;
id=353.000000;
};

Once changed you will need to re-start your mission or continue your campaign for the changes to take effect. These changes are often reset at the beginning of new missions/campaings requiring you to alter the new cfg file for that particular mission.

Bonus Level:
After you beat the game (I destroyed the second scud and killed Guba) Watch through all the credits and let it go through all the loading screens. After the credits are over it will start a scene with the black ops guy talking on the phone to Dave (Armstrong, the inf. guy) After the scene you get to fly a Cessna into the Everon airport and pick up all the other characters that you got to play and take them to a pub.

All Missions:
At the First Screen. Hold the left click and press the minus key on the number keypad then type campaign to open all campaigns

Finish level:
At the start of any level type skip mission i don't know if you are supposed to have a space between skip and mission.

NOTE! you have to hold down the left "shift" and both "minus" buttons in three seconds before you can type the code.

Unlimited ammo ,and weapons
Durring game play "Alt+ ~"to exit to windows, go to your "Operationflashpoint/users/username/saved/temp"directory then open 1985.sqc file
with note pad, in there is where your progress in the campaign is kept.
look for you campaign title and the find this entry--

side="WEST";
idGroup=1.000000;
id=1.000000;
take note of the "idgroup" value
and the "id" value.

now goto \OperationFlashpoint\Users\username\Saved\campaigns\1985
open weapons.cfg file using note pad
look for "david armstong" and edit his "idgroup" and "id" values acording to 1985.sqc values

whille your there you can crank up anybodys weapons,including your own or exchange weapons.
BE SURE TO BACK UP ANYTHING BEFORE YOU EDIT.
save the changes you made and return to your game and restart the currnt campaign
if you did it right it will work flawlessly.
the same can be done with "red hammer"