A small business that is at least 51 percent owned and controlled by veterans with a service-connected disability rating, certified through the SBA's VetCert process. It unlocks SDVOSB set-asides and sole-source awards, and the certification is especially strong at the VA, which runs its own veteran-first contracting preference on top of the government-wide goal. VOSB, veteran-owned with no disability requirement, is a smaller, related category with its own narrower set of set-asides.

In a sentence

"This solicitation is a total set-aside for Service-Disabled Veteran-Owned Small Business concerns." Only certified SDVOSBs may bid, and the VA in particular runs enough of these that the certification can be worth pursuing on its own.