The special rate back pay case involves employees receiving that form of bonus pay during the years 1982-1988 who had their raises denied or capped under a policy in effect at that time. Many potentially affected individuals have been champing at the bit for years waiting for a resolution of the suit. However, the National Treasury Employees Union, which sponsored the suit, says that for the meantime, those who are in the class-or who think they should be-need do nothing. Payments potentially could go out in the autumn, although a challenge to the amount calculated for an individual could delay the payment for that person for many more months.