Here’s how Gibson defines the term:
THE VINTAGE ORIGINAL SPEC SERIES, OR V.O.S., HAS A NEW, PROPRIETARY FINISHING PROCESS WHICH YIELDS THE GENTLY AGED PATINA OF A VINTAGE CLASSIC. ALSO, A REVOLUTIONARY HANDCRAFTING PROCESS ENHANCES COMFORT AND PLAYABILITY GUITARS. SOLID MAHOGANY BACK, HISTORICALLY ACCURATE LONG NECK TENON FOR SUPERIOR STRENGTH AND SUSTAIN, PERIOD CORRECT NECK PROFILES, HARDWARE AND ELECTRONICS, AND 100% NITRO-CELLULOSE LACQUER ARE AMONG SOME OF THE FEATURES OFFERED IN THE GIBSON CUSTOM V.O.S. SERIES.