... From version 1.1 on the output routine tests if the columns RA_CORR and DEC_CORR are already present in the input/output file. Depending on the presence of these columns it will either add them or modify them. ... The following keywords are added to the table: RAOFFSET , DEOFFSET , which indicate the offsets in RA and DEC used to correct the psoitions; RAOFFERR , DEOFFERR (the associated statistical errors) and LIK_HOOD (containing the likelihood statistic) and NMATCHES . ...