||Amount of prior special basic pay supplement established for a defined subcategory of employees in a pay system or subsystem as a prior secondary supplement. The prior special basic pay supplement applies in lieu of any applicable prior standard basic pay supplement that is a lower amount. The supplement is a regular, fixed payment for nonovertime hours of work that is creditable as prior basic pay for retirement purposes, excluding any type of prior premium payment or differential that is triggered for working certain hours of the day or week or for performing certain types of work. Includes prior GS special rate supplement or equivalent prior supplement. Express amount using same prior pay basis as used for prior basic pay rate.