Here is a late series, early pillars type Mexico 1 real coin. Fairly detailed. Assayer O. Carlos y Johana. Date range around 1553 to 1570? Carlos' reign ended much earlier (1556?) but it looks like the Mexico mint kept pushing out his name until 1571. According to a Sedwick document. But here is my question.... I see similar Mexico 1 real coins from this date range with 'REGS' in the legend and some with 'REGES', but I cannot see any other examples that use the abbreviation 'RGS'. (almost looks like they used an 8 for an S here). Does my 'RGS' abbreviation help to narrow down the date range? And yes the O assayer is tricky for exact dates as there is a lot of uncertainty about this assayer's exact tenure dates. So.... 'RGS' abbreviation.... does it carry special significance?