GASP Animation Qestion

Hi People, stripping down the Epic Game Animation Sample Pack, just a quick question on Epics naming convention, there is a lot of double or more of the same animation in the sample pack where the player is just lifting of a different foot, so I am removing one set of animations where the player is only lifting off the right foot, but I am trying to figure out with one is witch such as they all seem it be the same.
M_Neutral_Crouch_Pivot_RL_Lfoot
M_Neutral_Crouch_Pivot_RL_Rfoot
M_Neutral_Crouch_Pivot_RR_Lfoot
M_Neutral_Crouch_Pivot_RR_Lfoot

I am trying to figure out what the RL_ and the _Rfoot mean in refence to the animation,