Double-sideband suppressed-carrier transmission (DSB-SC): Transmission in which (a) frequencies produced by amplitude modulation are symmetrically spaced above and below the carrier frequency and (b) the carrier level[?] is reduced to the lowest practical level, ideally completely suppressed.
Note: DSB-SC transmission is a special case of double-sideband reduced carrier transmission.
... Cross tube station (for the Jubilee Line)
Holborn tube station (for the Aldwych branch of the Piccadilly Line)
These stations once served by the Metropolitan Line, ...