(pronounced bug)
The Illuminating Engineering Society of North America [IESNA] introduced TM-15 -11 “BUG” (Backlight, Uplight and Glare) classification of outdoor lighting fixtures to ensure that only well-shielded fixtures are used. No uplight for area and street lighting is allowed in any zone. The Model Lighting Ordinance (otherwise known as the MLO) uses BUG.
See also: Model Lighting Ordinance