Trim level

Automotive trim nomenclature is loosely identified with alphanumeric lettering on various exterior locations on automobiles manufactured internationally. Some of the commonly used designations are DX, LX, LS, EX, GL, SE, GT just to name a few. The exterior coding helps identify at what level the identified vehicle is equipped. Some of the more basic lettering used is DX, while luxuriously equipped vehicles can be seen with LS, GT, or SE.

The alphanumeric coding began to appear on Japanese and European vehicles beginning in the mid 1970s, while North American vehicles used names for vehicles, such as Mustang, Torino, Impala, Chevelle, Barracuda, and Imperial. North American vehicles that were specially equipped did use special alphanumeric coding for exclusive vehicles like the "SS" designation on Chevrolet products, and Ford used the "GT" term on the high performance version of their products. GM did begin using alphanumeric coding to denote special handling packages installed on performance vehicles, such as "Z28" on the Camaro, the Buick GS, or the Oldsmobile 442, and currently uses the designation "Z71" on the Suburban and Tahoe. Toyota also uses this naming convention on the SR5.

During the 1970s and 1980s, some manufacturers used a word to denote a luxury level of equipment installed in large sedans, such as the word "Brougham" used by Cadillac Brougham, the Holden Brougham, and on the top level Nissan Cedric/Nissan Gloria.

...
Wikipedia