Parameters pname Specifies the symbolic name of the parameter to be set.
Six of the twelve storage parameters affect how pixel data is returned to client memory, and are therefore significant only for glReadPixels commands. If true, byte ordering for multibyte color components, depth components, color indices, or stencil indices is reversed. This parameter is significant for bitmap data only. 8a components or indices. The word component in this description refers to the nonindex values red, green, blue, alpha, and depth.