First press the ~ key (just like in Quake and Q2). Then enter the
code:

/health 999             Health 999
/wuss                   All weapons
/superfuzz              God mode
/nocollision            No clip mode
/wallflower             No target

     Likewise for the heligun (bind to different key).

/spawn magnum           Gives the Magnum
/spawn shotgun          Gives the Shotgun
/spawn assaultrifle     Gives the Assaultrifle
/spawn rocketlauncher   Gives the Rocketlauncher
/spawn sniperrifle      Gives the Sniperrifle
/spawn heligun          Gives the big gun from the chopper

/spawn reactiveshields  Gives the ReactiveShield
/spawn rockets          Gives Rockets
/spawn coin             Gives a coin
/spawn health           Gives a healthpack
/spawn cookies          Gives a pack of cookies
/spawn lensflare        Makes a light-effect

Type in for two secret weapons:-

     Go to the console (Press ~) and type: "Give Thrallgun" bind it to
an easily accessable key 'M' eg. Bind M "use thrallgun" (has two modes
of fire)

All are items that you can get via "/spawn " :

ChainGun                chaingun (the one you get with the 5-key)
BlueCard                blue Identcard
OrangeCard              orange "
YellowCard              yellow "
GreenCard               green "
IdentCard               ??
Code                    ??
KeyRing                 small key
MoneyBag                bag from bank robbery
Dollar                  coin
Evidence                papers with evidence
Decoder                 ??
PulsePart1              first part of Pulse Cannon
PulsePart2              second "
PulsePart3              third " (as soon as all three parts are
                        picked up, the weapon is ready)
Chemsuit                protection suit
Blueprints              blueprints from constructionsite
U4 sample               sample from chemplant
Envelope  
Silencer                silencer for standard gun