Kovacs, F. Armenian Coinage in the Classical Period. CNS 10. (Lancaster, PA, 2016).

U Unique: Only 1 specimen known to the author
RRR Extremely Rare: 2 - 9 known to the author

RR Very Rare: 10 - 19 known to the author

R Rare 20 - 49 known to the author

S Scarce 50 - 99 known to the author

C Common: 100 or more known to the author

Also see:
Kovacs Armenia I
Kovacs Armenia II
Lindgren-Kovacs