(a) For each determination to pay a recruitment incentive under this subpart, an agency must document in writing—

1. (1) The basis for determining that a position is likely to be difficult to fill, as determined under § 575.106;
2. (2) The basis for authorizing a recruitment incentive; and
3. (3) The basis for the amount and timing of the approved recruitment incentive payment and the length of the required service period.