• xveladd: Returns the additional x-velocity that is added to the player's own when he is KOed. (float)
• yveladd: Returns the additional y-velocity that is added to the player's own when he is KOed. (float)
• type: Returns the type of the hit: 0 for none, 1 for high, 2 for low, 3 for trip (ground only).
• animtype: Returns the animation type of the hit. (0 for light, 1 for medium, 2 for hard, 3 for back, 4 for up, 5 for diag-up)
• airtype: Returns the type specified in the HitDef for an air hit.
• groundtype: Returns the type specified in the HitDef for a ground hit.
• damage: Returns the damage given by the hit. (int)
• hitcount: Returns the number of hits taken by the player in current combo. (int)
• fallcount: Returns the number of times player has hit the ground in the current combo. (int)
• hitshaketime: Returns time player is "frozen" during the hit. This number counts down by 1 for each game tick, and stops when it reaches zero. (int)
• hittime: Returns time before player regains control and returns to an idle state after being hit. This counts down by 1 per game tick, as long as hitshaketime (see above) is greater than 0. It stops counting down when the value reaches -1. (int) "GetHitVar(hittime) < 0" is equivalent to the HitOver trigger.
• slidetime: Returns time that player slides backwards (on the ground) after the hit. (int)
• ctrltime: Returns time before player regains control after guarding the hit. (int)
• recovertime: Returns time before player gets up from liedown state This number counts down to 0 for each game tick, and will count down faster if buttons are hit. (int)
• xoff: "Snap" x offset when hit (deprecated)
• yoff: "Snap" y offset when hit (deprecated)
• xvel: Fixed x-velocity imparted by hit. (float)
• yvel: Fixed y-velocity imparted by hit. (float)
• yaccel: y acceleration set by the hit. (float)
• chainid: Player-assigned chainID for last hit taken. (int)
• guarded: True if the last hit was guarded, false otherwise.
• isbound: True if the player is the subject of an attacker's TargetBind controller. Useful to prevent being stuck in thrown states. (int)
• fall: True if falling, false otherwise (int)
• fall.damage: Damage taken upon fall (int)
• all.xvel: x velocity after bouncing off ground (float)
• fall.yvel: y velocity after bouncing off ground (float)
• fall.recover: True if player can recover, false otherwise.
• fall.recovertime: time before player can recover. (int)
• fall.kill: value of fall.kill parameter in attacker's hitdef. (int)
• fall.envshake.time: See below. (int)
• fall.envshake.freq: See below. (float)
• fall.envshake.ampl: See below. (int)
• fall.envshake.phase: Returns values set by the fall.envshake.* parameters in an attacker's hitdef. (float)

trigger1 = GetHitVar(yvel) < -5.5
  Triggers if the hit's specified y velocity is less than -5.5.

[State VelSet]
type = velset
trigger1 = 
x = gethitvar(xvel)* facing

fall.envshake.ampl = var(5)

[State 9876, 0]
type = ChangeAnim
trigger1 = GetHitVar(fall.envshake.ampl) = 1
value = 9876
persistent = 0

fall.envshake.ampl = ID

[State 9876, 0]
type = VelSet
trigger1 = PlayerIDExist(GetHitVar(fall.envshake.ampl)) ;check that the value snagged from the HitDef is actually a PlayerID
trigger1 = PlayerID(GetHitVar(fall.envshake.ampl)),StateNo = 9996
value = 10
persistent = 0

Gethitvar(isbound) will bug if P2 performs the move with the TargetBind controllers AND the movetype is set to I.
Under this instance, P1 will see Gethitvar(isbound)=0 and eventually go back to his owns SelfState if using a trigger like !Gethitvar(isbound).
In the same scenario, if P1 performs the same move instead, P2 will see Gethitvar(isbound)=1 and still be under P1's custom state, hence the bug with the internal engine

In this scenario, TargetBind is working fine and positioning the player in the corresponding screen position, but since the movetype is set to I (no attack), P1 gets a different gethitvar(isbound) data than P2.

The "fix" to this bug is to ensure that any state with TargetBind controllers are set as movetype=A, otherwise it will work only for P1 but not for P2

More details here:
http://mugenguild.com/forum/topics/p1-not-bound-if-p2-initiates-hold-possible-bug-gethitvarisbound-185393.0.html