Writing recenter(1) to this object is a SET command that recenters the receive Plesiochronous/Doppler buffer. This buffer absorbs the small, slow clock drift between the satellite-recovered timing and the terrestrial-side clock, and over time it can drift toward one end of its range; recentering it manually restores maximum headroom before it would otherwise overflow or underflow and cause a buffer slip. An admin who notices the buffer creeping toward its limit on a long-duration stable link would SET this object to 1 as a preventive measure rather than waiting for an actual slip/alarm event.