On a counterweight fly system, most lockrails have holders for 3"x5" index cards (note cards) for batten identification, known as the Index Strip. The linear light fixtures or line of sockets illuminating this area are Index Strip Lights.
Index Strip, from Tiffin Scenic Studios, Inc..
Another picture, from http://www.majortheatre.com/rigging.html.
PDF of one manufacturer's product: http://www.ssrconline.com/index_light.pdf.
Index Strip, from Tiffin Scenic Studios, Inc..
Another picture, from http://www.majortheatre.com/rigging.html.
PDF of one manufacturer's product: http://www.ssrconline.com/index_light.pdf.