The general service submarket includes standard incandescent A-type lamps, incandescent halogen, CFLs, and LED replacement lamps. These omnidirectional lamps, are some of the most widely recognized and, while the vast majority of these lamps are used in general service applications, some, due to their low cost and popularity, are also found in downlight and track lighting applications as discussed in Section 3.3.3, which covers the directional submarket. Additionally, a small number of these GSLs are used in outdoor submarkets, discussed in Section 3.4.