iddqd = God Mode
idfa = Ammo & weapons
idkfa = Ammo, keys & weapons
idclip = Clipping mode on. Walk through walls! Toggle this mode back off to pick up items or use switches and doors. This one only works with Doom II. Type idspispopd instead for Doom
Iidchoppers = Get the chainsaw (and a cryptic message)
iddt = With the AutoMap showing, cycles between normal map, full revealed map, and a full map showing the objects and enemies
idbeholds = Get berserker pack
idbeholdv = Get temporary invulnerability
idbeholdi = Get temporary invisibility
idbeholda = Get full AutoMap
idbeholdrv = Get antiradiation suit
idbeholdl = Get light-amplification visor
idclev = Followed by episode and level number, warps to that level
idmypos = Display coordinates and heading