Hi Rhona. The number after D O C is probably a mold number or a code of some kind, but definitely not the date. Both 1830 and 1880 are too early for your bottle, and 1930 is too late. Having said that, some companies (not necessarily bottle makers) used a code for dates, but I don't know if this manufacturer did that.
As far as what "common " is, it refers to the number of bottles that have been found and/or the availability of a given bottle. Some bottles may be found in large numbers locally, but be hard to find 50 miles away.
As far as what "common " is, it refers to the number of bottles that have been found and/or the availability of a given bottle. Some bottles may be found in large numbers locally, but be hard to find 50 miles away.