Additions by Francesco Orsenigo (159, 184, 788)

Notes:
Each code pointer is listed only once. The two "check line of sight"
pointers are different, but with the same effect. Only one pointer has
a function unknown to me. All pointers which make sounds ONLY can be used
anywhere, but they may not always work. Weapon code pointers are restricted
to the weapon frames, and the monster code pointers are used anywhere else.
For the Mancubus firing pointers, the directions are as viewed from the
mancubus, so a "left" fireball will go past you to the right if you do not
move. That should clear things up.

Weapon Code Pointers:

1 - Light restore (after flash)
2 - Weapon bobbing pointer
3 - Weapon select pointer
4 - Weapon deselect pointer
6 - Player Punch
9 - Last shooting frame (if fire button still held, jump back to first
shooting frame instead of frame with this pointer)
14 - Player Pistol shot
17 - Light flash (dim)
22 - Player Shotgun blast
31 - Light flash (bright)
36 - Player Double-Barrel Shotgun blast
38 - Check ammo (If 1 or 0 shells left, skip reloading frames and select
different weapon)
39 - Play sound "dbopn"
41 - Play sound "dbload"
43 - Play sound "dbcls"
52 - Player Chaingun shot (check ammo; don't go to -1 ammo, change weapon)
60 - Display firing frame
61 - Player launch rocket
71 - Player use chainsaw
77 - Player fire plasma bullet
84 - Play sound "bfg"
86 - Player fire BFG shot

Monster Code Pointers:

119 - BFG blast effect
127 - Radius explosion
157 - Play pain sound
159 - Plays "PLDETH"
160 - Dead body mode
166 - Play sound "slop"
174 - Wait to wake up
176 - Standard walking code pointer
184 - Turn to face the player's direction
185 - Trooper pistol shot
190 - Play death sound
243 - Archvile walking code pointer (check to resurrect monster)
255 - Play sound "vilatk"
257 - Create archvile flame at target
264 - Archvile blast target
281 - Play sound "flamest"
282 - Unknown (used only in flame frames (281... and 791...))
285 - Play sound "flame"
316 - Revenant fireball homing (and smoke trail) code pointer
336 - Play sound "skeswg"
338 - Revenant punch - play sound "skepch" if hit
341 - Launch revenant fireball with possible homing (and smoke trail) effect
376 - Play sound "manatk"
377 - Mancubus shoot 2 fireballs: one straight, one left
380 - Mancubus shoot 2 fireballs: one straight, one right
383 - Mancubus shoot 2 fireballs: one left, one right
397 - Magic Code Pointer
417 - Chaingun guy or SS nazi shoot chaingun
419 - Check line of sight to stop firing
454 - Imp shoot fireball or scratch at close range
487 - Demon bite
506 - Cacodemon shoot fireball or bite at close range
539 - Baron of Hell or Hell Knight shoot fireball or scratch at close range
590 - Lost soul attack - attack sound REQUIRED or game will crash
603 - Play sound "metal"
616 - Spiderdemon shoot chaingun
618 - Check line of sight to stop firing
635 - Play sound "bspwlk"
648 - Arachnotron shoot plasma bullet
676 - Play sound "hoof"
685 - Cyberdemon launch rocket
711 - Spawn lost soul
718 - Spawn 3 or 4 lost souls
774 - Magic Code Pointer and Dead Body mode
779 - Play sound "bospn"
780 - Play sound "bosdth" and make explosions (frames 799-801) about 320
units south of object
783 - End level
785 - Play sound "bossit"
786 - Fire spawn cube - Landing REQUIRED on level or game will crash
787 - Play sound "boscub"
788 - Check for spawn point (spawn monster)
801 - Create explosion (frames 127-129)