=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-Jun-1991 St Jean-Port-Joli 970/066 RLR(1973) is 21.8m below BM CLXXVII =========================== FOLLOWING PSMSL DOCUMENTATION ADDED 19-Aug-2010 Primary benchmark 1968-1978 is BM CLXXVII. Primary benchmark 1979 onwards BM POJO-2-1967. This does not alter the RLR factor of 6.770m. Last data April 1979.