How can we get detailed explanation of obvervation variables?

Hi~ Thanks for your great work.
I am playing with the locomotion soccer environment. But I have no idea about the meaning of some observation variables:
They look like the following:
```
"team_goal_back_right", # (1, 2) [[20.39657422 -5.54516916]]
"team_goal_mid", # (1, 3) [[ 11.73723908 -10.76243655 1.67126411]]
"team_goal_front_left", # (1, 2) [[ 3.07790393 -15.97970393]]
"field_front_left", # (1, 2) [[-56.03425312 20.39720981]]
"opponent_goal_back_left", # (1, 2) [[-49.91189073 34.54660858]]
"opponent_goal_mid", # (1, 3) [[-41.25255558 39.76387596 1.67126411]]
"opponent_goal_front_right", # (1, 2) [[-32.59322043 44.98114335]]
"field_back_right", # (1, 2) [[26.51893661 8.6042296 ]]
```
Where could we find a detailed meaning of these variables?
Thanks!