Complex sentence: The STLD was established on 30 October 1974 as the Society of Television Lighting Directors to promote discussion on techniques and the use and design of equipment, and at its AGM in March 2009 it became the Society of Television Lighting and Design.
Split into simpler sentences: The STLD was established on 30 October 1974 as the Society of Television Lighting Directors to promote discussion on techniques and the use and design of equipment. At its AGM in March 2009 its name was changed to the Society of Television Lighting and Design.