(a) DRC's can be added to the following PIA's when used in computing the following benefits:
(1) Tier I PIA used in computing a retirement employee annuity.
(2) Overall Minimum PIA used in computing a retirement employee annuity.
(3) Survivor Tier I PIA used in computing a widow(er), remarried widow(er) or surviving divorced spouse annuity based on age or disability.
(4) Employee RIB PIA used in computing a widow(er), remarried widow(er) or surviving divorced spouse annuity based on age or disability.
(5) RLS PIA used in computing the amount of the residual lump-sum payable (as explained in part 234 of this chapter).