This name was used by Ford in the 1970s to describe its bodies which had frameless door glass like a hardtop, but retained a center pillar like a sedan. The 1972-1976 Torino sedans and wagons were of this type, as were the 1975-1979 Lincoln Town Cars. When GM introduced a similar style on their intermediates for 1973–1977, they called the two-doors Colonnade Hardtop Coupe and the four-doors, in a triumph of ad agency gibberish, Colonnade Hardtop Sedan. The 1976 Buick Century sedan used this configuration. Before Ford introduced its "Pillared Hardtops" in the early seventies, GM had the same body style available on its "C" body cars (Buick Electra 225, Oldsmobile 98 and Cadillacs) from 1965 to 1970.
GM called them "semi-thin pillar sedans" as they had a slightly larger center pillars than other GM sedans (that were called "thin pillar sedans") but they had no window frames like the "thin pillar sedans" had.