Numerical designations are often au

Numerical designations are often augmented (or replaced) by written characterizations, although these can be nebulous. Spot lamps typically have a nominal beam angle of 20° or less, whereas flood lamps typically have a nominal beam angle of 25° or more, but there is no accepted standard for further numerical sub­ classification. Common terms include very narrow spot (VNSP), narrow spot (NSP), spot (SP), wide spot (WSP), narrow flood (NFL), flood (FL), or wide flood (WFL), but there is no industry standard defining these descriptors in terms of beam angle, and there is sometimes overlap in the categories across different manufacturers. ANSI C78.379­2006 recommends that distributions are denoted with both the descriptor and the beam angle, which allows the numerical designations to be compared (e.g., FL40 for a flood lamp with a 40°beam angle, or NSP9 for a narrow spot with a 9° beam angle).