DR, DC - the shift in rows and columns of the target image from the reference images.
GALBOX - the location of the galaxy (determined by eye) the pixel locations of the sr, sc, nr, nc are printed.
MAGDIFF - the magnitude difference between the target and reference image uncompensated for any exposure time difference. If it is negative the target image is fainter than the reference.
MAGDIFF2 - the magnitude difference between the target determined by the correlation method if one star is found.
MAGDIFF3 - the magnitude difference between the target and the reference compensated for the exposure time difference (if any).
NMATCH - the number of stars that are in the same relative relationship. If the number is greater than 1, it was set by sn_fidmatch.
MFWHM - the mean fwhm in pixels of the fiducials
MNSTAR - the number of fiducial stars detected in the target.
MSKY - the mean sky value of the target determined from four boxes at the corners of the image.
MSKYSIG - the rms fluctuation of the four sky values used for MSKY giving an idea of the sky gradient.
MAG_CAND - the instrumental photometry of candidate all photometry is done with a 8 pixel radius.
NEWBOX - the galaxy box (see GALBOX) in pixel coordinates on the target image. If nr and nc are different then not all the galaxy has been observed.
SKY_CAND - sky value from photometry of candidate.
FWHM_CAND - the fwhm of the candidate
REJMAG - the magnitude difference between stars in the reference image and the same position in the difference image.