Convention for identifying bits in a mask/flags image in FITS

Abstract

Describes a convention used by the Vera C. Rubin Observatory and other projects for the identification of individual bits in a "flags image" or "mask image" - an integer-valued image in which individual bit planes are assigned to represent a set of Boolean values associated with individual pixels in an accompanying main image. The convention supplies a symbolic name for each bit plane, and optionally a description string. This convention applies to the serialization of such a "flags image" in FITS.