When values of the Stokes parameters are mapped, an axis with the CTYPEn value 'STOKES ' is used to describe which Stokes or correlator parameters are displayed in the images. The values and the parameters they denote are shown in Table 5.3.
X and Y are linear polarizations with fixed orientation relative to the antenna. In the interferometry proposal, X is horizontal and Y vertical. R and L refer to right and left circular polarization. The convention has been suggested that -2 be used to refer to left circularly polarized images and -1 to right circularly polarized images. The definitions of circular polarization follow the IEEE convention; right circular polarization corresponds to the electric vector of an approaching wave rotating clockwise. This convention should be noted in the comments; use of the opposite convention is not unknown.