ESS routing to vacant position for manager RH_ACT_LEADING_POSITION

[Rick Sample]

I am reviewing the code in RH_ACT_LEADING_POSITION.
I see 
* consider vacant positions flag in table T77S0
* wflow-vapos
  PERFORM re77s0(mstt77s0) USING 'WFLOW' 'VAPOS' lv_sw_vapos lv_subrc.

If populated in table T77S0, "wflow" "vapos" does what? 
Skips this valid position with no holder and goes one org up?

If so, what is the value for GSVAL in this table T77S0?

Rick
4.6c