Things the Machinima Game Type allows you to do:

• Un-hide object state - For hidden objects, when a player steps into the mach_show boundary, should it reappear only when inside the boundary, or until the map is reset?
• Flag Carry Type - Standard (flag/magnum) or Speedflag (strapped to back - still experimental)

Forge labels (again, for things that can't be done normally via Forge, but could be useful in a machinima map)

• mach_spawn - spawns a non-forgeable object based on the User Data setting: List if below
• mach_trigger - 'turns on' things like the turrets, etc. Tied to spawn sequence, so you can have certain items spawn based on your which one you 'activated'. Dominion items can still be set to a specific team if teams are enabled. Monitors can also display different presets (sorry, no custom text) via the User Data setting. Things such as "Resupplying" and "Fortifying" can be displayed. Turret monitors don't have anything other than a readout for a turret. Valid values of the monitor's User Data are 1-6. A player must stand inside the boundary of mach_trigger to activate things. Thus it's useful to add a second label, mach_show_boundary so you can see the boundary for the trigger (off camera players could easily activate this).
• player_appearance - Changes appearance based on User Data: 1 = Spartan, 2 = Flood, 3 = Invisible (just weapons and armor ability are visible). Like mach_trigger you must step inside the boundary to change appearance.
• player_scale - Will scale an item by its User data Setting. Starts with 1 (25%) and increases to 11 (300%) in 25% increments. Like mach_trigger you must step inside the boundary to change size. Note that while players can still be hurt at any size, their collision stays the same size. Something fun to try: When you change scale it's not instant, the player grows or shrinks. Try lining a bunch of these up and timing it perfectly to grow from 25% to 300% without any stuttering.
• attach_parent and attach_child. These are tied with User Data. For example, if a Banshee is set to attach_parent and has a User Data of 1, and a Mantis is set to attach_child and has a User Data of 1, the Mantis will attach itself to the Banshee. Note that the child object will have no collision.
• mach_hide, mach_delete - Makes an object invisible or deletes it entirely. Spawn sequence can delay this. User Data can tie to object_show to un-hide things on a per-item basis
• mach_show - Shows any item that has been hidden and has the same User Data setting as mach_hide
• mach_scale - Will scale an item by its User data setting. Valid numbers are 1-100, and each number is 1/2 of the scale size. For example, a User Data setting of 25 will scale an item to 50% of its size, while 100 would scale it to 200%. Physics and collision do not scale, so for example a Mongoose set to 50% will still have a collision box like normal, and it will easily tip over when driving.
• mach_dropflag - Drops the flag, or any other object that cannot normally be dropped, such as certain versions of the extractor
• mach_show_boundary - will show any boundary for an object with this label. Useful if you have your player_scale or player_appearance objects off-camera and want to have actors (players) run off screen to "change clothes". Can also be used simply to show a boundary. For example, this could be combined with mach_dropflag to have a 'mock game' of CTF for the filming.
• reset_map - Ends the round (to reset map)

mach_spawn User Data values (number corresponds to the number you should use to get this item to spawn):

• 0 - Oddball
• 1 - Extractor with bomb attached: can be picked up, must walk through mach_dropflag to drop it (it returns to the spawn point)
• 2 - Bomb: it can't be picked up, it doesn't animate like in Extraction, and constantly makes noise, but hey, there you go
• 3 - Extractor without bomb: can be picked up, must walk through mach_dropflag to drop it (it returns to the spawn point)
• 4 - Target Designator
• 5 - King of the Hill explsion: An effect that loops. It's red, has two "spires" coming out of it, and will drain your shields if you get too close.
• 6 - Extraction effect: An electrical, skinny spiral effect about twice the size of a spartan. It happens in extraction when the extraction containers appear
• 7 - Flag: When teams are enabled you can set the mach_spawn item to any team color and the flag will be that color. In FFA it's black. Anyone can pick it up, but it can only be dropped by walking through mach_dropflag
• 8 through 15 - These are the alternate skins for in-game weapons that can be unlocked through specializations. None of the preorder or DLC skins are available here. Don't want to make waves with 343i/Microsoft.

Thanks to...

Teancum