Effective April 16, 2015, the Postal Service™ is revising the Employee and Labor Relations Manual (ELM) section 436.2 to clarify the exception which allows uncapped annual leave to be recredited, relative to the processing of a back pay claim.

4 Pay Administration
430 Basic and Special Pay Provisions
436 Back Pay
436.2 Limitations
[Revise the text of 436.2 to read as follows:]
Limitations to corrective entitlement are as follows:
a. Any amount that the employee earned in new employment or in an enlarged part-time employment to replace Postal Service employment must be deter­mined and offset against the amount of the reimbursement to which he or she would be entitled.
b. Back pay is allowed, unless otherwise specified in the appropriate award or decision, provided the em­ployee has made reasonable efforts to obtain other employment, as follows (see also 436.42f).
(1) Job applicants not hired by the Postal Service must immediately make reasonable efforts to obtain other employment.
(2) Separated employees, or employees on indefinite suspension, are allowed 45 days before they must make reasonable efforts to obtain other employment.
Exception: Postal Service employees eligible for veterans’ preference are not required to make rea­sonable efforts to obtain other employment while pursuing an administrative appeal with the Merit Sys­tems Protection Board (MSPB).
c. No back pay is allowed for any period during which the person was not ready, willing, and able to perform the duties of the Postal Service position.
d. Leave that is credited as a result of the corrective action may not exceed the maximum amount of leave to which the employee was eligible (see 512.321).
Exception: Uncapped annual leave is credited, if ordered, by the Equal Employment Opportunity Commission or for employees eligible for veterans’ preference by the MSPB.
e. The employee is not entitled to: (1) increases in pay resulting from deferment of step increases due to un­satisfactory service or (2) salary increases resulting from ranking action.
f. Any claim made by a Postal Service employee or his or her authorized agent or attorney for back pay must be submitted to the appropriate office within six full years after the date the claim first accrued.

via ELM Revision: Back Pay Limitations.