RNAV-M in SAN
Was holding short of RWY 27 today and heard a Horizon 175 check on with tower on the RNAV-M 27. Both of us had never heard of a “M” approach and it caught us off guard. Is this a special issue, Horizon only, approach or did we hear wrong? Could anyone shed light on what’s required to shoot it and maybe even the minimums for SAN?