RCMAC stands for recent change memory administration center, sometimes mistakenly called recent change message accounting center, in late 20th century Bell System parlance, or recent change memory administration group (RCMAG).
Recent change memory administration center, in late 20th century Bell System parlance, an organization of people in a phone company responsible for programming the service and features purchased by customers into the central office; sometimes mistakenly called: "recent change message accounting center"