Clarification questions on ocs2 observation state details!

[sinaaghli]

I'm curious on ocs2 msg details here

;; Normalized Centroidal Momentum: [linear, angular] ;;
   (0,0)  0.0     ; vcom_x
   (1,0)  0.0     ; vcom_y
   (2,0)  0.0     ; vcom_z
   (3,0)  0.0     ; L_x / robotMass
   (4,0)  0.0     ; L_y / robotMass
   (5,0)  0.0     ; L_z / robotMass

the comment on top of the message says Normalized Centroidal Momentum: [linear, angular] where as comments on the following lines state first three components are linear velocities and next three seem to be rotational velocities, rather than momentum? Another question is that rotational components are stated as L_x / robotMass which I'm assuming L_x represents rotational moment? but why is it divided by robotMass rather than inertia around x-axis?

[sinaaghli]

Sorry, two more questions:

1. is base here world fixed frame or body fixed frame?
2. which frame are the forces relative to?