The terminology in question is "high/full cutoff": * https://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightpollution/lightpollution.asp https://www.lrc.r

The terminology in question is "high/full cutoff": * https://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightpollution/lightpollution.asp https://www.lrc.rpi.edu/programs/nlpip/lightinganswers/light... * https://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightpollution/cutoffclassifications.asp https://www.lrc.rpi.edu/programs/nlpip/lightinganswers/light... There are standards (RP-33-99, RP-2) from folks like: * https://en.wikipedia.org/wiki/Illuminating_Engineering_Society https://en.wikipedia.org/wiki/Illuminating_Engineering_Socie... * https://energycodeace.com/site/custom/public/reference-ace-2019/index.html#!Documents/64mandatoryrequirements.htm https://energycodeace.com/site/custom/public/reference-ace-2... * https://www.shine.lighting/threads/122/ https://www.shine.lighting/threads/122/ * https://www.denvergov.org/files/assets/public/doti/documents/standards/pwes-012.2-street_lighting_design_guidelines.pdf https://www.denvergov.org/files/assets/public/doti/documents... IES TM15 11: * https://www.youtube.com/watch?v=EVPbuq4g5W4 https://www.youtube.com/watch?v=EVPbuq4g5W4 * http://www.escolighting.com/PDFfiles/BUG_rating.pdf http://www.escolighting.com/PDFfiles/BUG_rating.pdf Generally you don't light to illuminate more that 60˚ from the nadir of the lamp: * https://en.wikipedia.org/wiki/Nadir https://en.wikipedia.org/wiki/Nadir