[Eames]

He was talking about this

// dmflags -- flags that can be set in the dmflags variable.
// ( enable as many of these as necessary -- Hammer)
set dmflags 0
//add dmflags 1 // DF_NO_HEALTH (1 << 0)
//add dmflags 2 // DF_NO_POWERUPS (1 << 1)
//add dmflags 4 // DF_WEAPONS_STAY (1 << 2)
//add dmflags 8 // DF_NO_FALLING (1 << 3)
//add dmflags 16 // DF_INSTANT_ITEMS (1 << 4)
//add dmflags 32 // DF_SAME_LEVEL (1 << 5)
//add dmflags 2048 // DF_NO_ARMOR (1 << 11)
//add dmflags 16384 // DF_INFINITE_AMMO (1 << 14)
//add dmflags 131072 // DF_NO_FOOTSTEPS (1 << 17)
//add dmflags 262144 // DF_ALLOW_LEAN (1 << 18 )
//add dmflags 524288 // DF_OLD_SNIPERRIFLE (1 << 19)
//add dmflags 1048576 // DF_GERMAN_SHOTGUN (1 << 20)

just add them up and you have your dmflags set