I did a search but could not find if this topic has been discussed before so here is the situation.

If I am on a LH flight and they need to upgrade people due to being oversold. Which order do they use to determine the upgrade? I would guess that it is Senators, FTL, *G, *S.

Others have suggested Senators, *G, FTL, *S.

Does anyone have either anecdotal experience or know for sure what the "rules" are?