Further to my email last night I now realised that I generalised from a
limited number of search results. Therefore some of the assertions I made
are misleading. Apologies.
What I have now discovered is that some of the systematically extracted
batches of marriages in Cornwall in the IGI , such as those for St Endellion
and St Columb Minor, were not complete lists of all marraiges. They left out
any marriage that had already been put into the IGI by an earlier LDS member
submission. It so happened that the family name I searched for had been
researched before the systematic extraction process, and submitted to IGI in
1973 as a separate batch which does not have an M number.
It is to be hoped that these entries are not lost when the existing
Familysearch site is replaced by the Beta (or some derivative of it with
better functionality).
Jeff