When you add a new ability or item ability it will have a default value for the Ability Index or Item State Index. This value can be changed to one that fits your Animator better but the following are the default Ability Index values used:

AbilityAbility Index
Jump1
Fall2
Height Change3
Die4
Revive5
Start Movement6
Stop Movement7
Quick Turn8
Interact9
Damage Visualization10
Pickup Item11
Ride12
Generic10000

The following are the default Item State Index values used for each Item Ability:

Item AbilityItem State Index
Aim1
Use2
Reload3
Equip4
Unequip5
Drop6

The following are the default Item ID values used for each Item:

Item
Item ID
Assault Rifle1
Pistol2
Shotgun3
Bow4
Sniper Rifle5
Rocket Launcher6
Body21
Sword22
Knife23
Katana24
Shield25
Frag Grenade41