Add the e-terms (elliptic component of annual aberration) to a pre IAU 1976 mean place to conform to the old catalogue convention.
rm,dm double RA,Dec (radians) without e-terms eq double Besselian epoch of mean equator and equinox
*rc,*dc double RA,dec (radians) with e-terms included
slaEtrms, slaDcs2c, slaDcc2s, slaDranrm, slaDrange
Most star positions from pre-1984 optical catalogues (or derived from astrometry using such stars) embody the e-terms. If it is necessary to convert a formal mean place (for example a pulsar timing position) to one consistent with such a star catalogue, then the RA,Dec should be adjusted using this routine.
Explanatory Supplement to the Astronomical Almanac, ed P.K.Seidelmann (1992), page 169. P.T.Wallace Starlink 31 October 1993