5 C.F.R. § 319.401
(a) General. SL positions may be in either the competitive or excepted service. This section only applies to appointments in the competitive service from a civil service register. Reassignments, promotions, transfers, and reinstatements to SL positions in the competitive service shall be made in accordance with applicable statutory and regulatory provisions. Employment of SL employees in the excepted service is covered by 5 CFR, part 302.
(3) Delegated authority may be terminated or suspended at any time by OPM for reasons such as, but not limited to:
(b) Recruitment.
(d) Records.