I am not certain, but brainstorming may help you a bit further.
use SM30, enter T077K, then click find maintenance dialog
you can at least see two with the same name, but they appear different in detail
V_T077K Vendor Account Groups
V_T077K_M Vendor Account Groups
In both views you can go into the detail of an account group
there double click a field status
put the cursor into a group then choose from menu Extras > Subgroup list > with item specification
you get a pop-up with the field name and a number behind.
I could imagine that this number represent the position in FAUSA field of T077K.
You may want to verify it yourself by changing a status of a certain field, then count the positions in T077K to see which position got changed and if this corresponds to the number next to the field name