Sanctuary was the diplomatic procedure by which Bajoran collaborators exiled per the Ilvian Proclamation were allowed to return to the planet. It was a courtesy rarely, if ever, extended to anyone, as collaborators were considered the lowest of the low on Bajor.
In 2370, Vedek Winn granted Kubus Oak sanctuary in exchange for his cooperation in an investigation of fellow Vedek Bareil. His name was fourth on the Ilvian Proclamation. (DS9: "The Collaborator")