Ground Sign: A freestanding sign with no visible support structure.
H Channel Letter: A dimensional letter with baffles at the center of the cross-sectional shape for support of neon tubing and mounting of transformers.High-Rise Sign: A tall freestanding sign, usually of pole design and construction.
Incandescent Bulb: A lamp that produces light through the application of electrical energy to a wire filament, which glows as it is heated. Its application is limited because it is a point source light, not easily diffused. It generates considerable heat, and its life span is limited by the filament degradation factor. Unlike neon tubing, it can be mass produced. (See fluorescent lamp; neon sign.)
Interior Signs: Signs that are located inside a building or other facility.
Illuminated Sign: A sign with electrical equipment installed for illumination at night or in early morning darkness, either internally illuminated through its sign face by a light source contained inside the sign or externally illuminated by reflection of a light source aimed at its surface.
ISA: International Sign Association. Trade association representing manufacturers, installers, users, and suppliers of on-premise signs and products. Located in Alexandria, VA.
