Japan Mint started to use these marks in 1979.
The following (constantly updated) table includes all currently known time coordinates for these marks.
AC - June 28, 1979
AB - November 28, 1979
BA - February 27, 1980
AJ - April 26, 1980
AL - April 29, 1980
AL - May 28, 1980
BC - May 28...
dark blue ribbon medal of honor
japan mint marksjapanese medal
japanese medal of honor
japanese medal with mark
japanesemedalsmarksjapanese order with mark
japaneseordersmarksletter-digitmarksonjapaneseordersandmedals
marked japanese medal
marked japanese order
two-letter marksonjapaneseordersandmedals
