Diamond service operated on the BMT Brighton Line while the north side of the Manhattan Bridge was closed for repairs from 2001 to 2004. Full-time local service was designated with a circle "Q" while weekday-only express service was designated with a diamond "<Q>". Other services have also used the diamond before and during the closure from 1986 to 2004; at least one (a brown "<R>") dated from a BMT special service using the same number (BMT 2) as the main service that became the "R" from 1986 to 1988.