Know any hidden mechanics? (Especially in AC1)

I know about (or I remember currently)

From AC1:

1. Air assassination
2. Vaulting
3. Hidden blade combat (counter; kill downed/chain kill terrified opponents)
4. (didn't try, just read) Hitting "attack" button when doing non-lethal counter changes it to lethal counter.
5. (I guess not really hidden, but I didn't know about it) You could lock on people to use knives even in AC1, even out of combat.
6. Locking on guards harassing someone will cause altair to taunt them.

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AC1-ACR:

1. Standing hidden blade high profile assassination has cool special animation. Font and back is different. (Not really hidden, but people don't generally use HP HB assassinations when standing) (maybe in latter games as well)

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AC2:

1. You could learn new combat moves for money in training arena.

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ACB-ACR:

1. Tool chain kill. (not sure if these were double as well)
2. Crossbow combat

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AC2-ACR:

1. Stolen weapons have special abilities. Fists can throw dust.
2. Fight with broom/fishing pole.

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AC3-ACRo:

1. Double tool kill (chain kill, but instead of kill, use tool [only some work]).
2. AC3 can do counter tool kill with things as snare, or similar, as well.
3. Double counter kill (if 2 attack at same time).
4. after jumping of something high enough, stop using "movement" sticks or wasd. Still hold High profile. You'll stay in special pose as long as you want. Same with killing with hidden blade, I don't remember exactly how now though.
5. You can steal 1 trowing knife in AC4-ACRo even though there's no ability to buy it. You can loot it back

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ACU:

1. (forgot about this one, sparked synapse reminded me) phantom blades can distract guards, like knives in ACS

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Any more?

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EDIT:

Forgot about these

~~AC3-ACRo engine:

1. Double tool kill (chain kill, but instead of kill, use tool [only some work]).
2. AC3 can do counter tool kill with things as snare, or similar, as well.
3. Double counter kill (if 2 attack at same time).~~

~~ACB-ACR:

1. Tool chain kill. (not sure if these were double as well)
2. Crossbow combat
3. Stolen weapons had special abilities~~

~~AC2:

1. You could learn new combat moves for money in training arena.
2. Knife combat/stolen weapons had special abilities~~

EDIT2 - Added few more.

EDIT3: Is there any way to do the "push away" they did in AC1 demo? With two hands.

EDIT4: AC2-ACR: you could throw dust.
You can take fishing rods and brooms as weapons.
Standing hidden blade high profile assassination has cool special animation. This applies to Ac1 as well and maybe latter games. (Not really hidden, but people don't generally use HP HB assassinations when standing) AC3-Ro: after jumping of something high enough, stop using "movement" sticks or wasd. Still hold High profile. You'll stay in special pose as long as you want. Same with killing with hidden blade, I don't remember exactly how now though.
You can steal 1 trowing knife in AC4-ACRo even though there's no ability to buy it.
ACU: forgot about this one, sparked synapse reminded me - phantom blades can distract guards, like knives in ACS

#EDIT5: reformatted the whole text