仔细选择照明设备对于确保室外照明的积极方面不会同时对当地居民造成滋扰至关重要。当设计照明应用时，可以考虑有关灯具光学的有意义的数据时，最好解决光污染、眩光、自然栖息地和夜间环境的问题。本文件定义了室外灯具的灯具分类系统（LCS），该系统向照明专业人员提供了有关特定感兴趣立体角内流明分布的信息。该系统克服了旧“切断”系统的许多缺点，旨在取代现在已弃用的系统。LCS还包括背光、上光和眩光（错误）等级。

A careful selection of lighting equipment is critical to ensure that the positive aspects of outdoor lighting do not simultaneously create a nuisance for local residents. The issues of light pollution, glare, natural habitat, and the nighttime environment are best addressed when meaningful data regarding luminaire optics can be considered as the lighting application is designed. This document defines a luminaire classification system (LCS) for outdoor luminaires that provides information to lighting professionals regarding the lumen distribution within solid angles of specific interest. This system overcomes the many shortcomings of the old "cutoff" system and is intended to replace that now deprecated system. The LCS also includes Back Light, Uplight, and Glare (BUG) ratings.