As used in this part:
Applicant means a person who signs an application for an annuity for himself, herself or for some other person.
Application means a form described in part 217 of this chapter.
Award means to process a form to make a payment.
Claimant means the person for whom an annuity application is filed.
Filing date means the date on which an application or written statement is filed with the Board.
Tier I benefit means the benefit calculated using the Social Security formulas and is based upon earnings, both in and outside the railroad industry.
Tier II benefit means the benefit calculated under a formula found in the Act and is based only upon railroad earnings.
20 C.F.R. § 218.2