These are based upon the occurrence of items from each type as seen in several major collections totalling over 20000 stamps. The ratings all refer to the country of use, thus a stamp marked as Very Common in Australia may be next to impossible to locate in the UK.
Note that these ratings apply to the basic Type shown, not to a particular set, or even individual value. In many cases, individual values are only known from a single copy, while other values in the same set are common. It should be used as a guide to the likelihood of finding an example of the Type in a reasonably sized collection of records from that country.
The meaning of the ratings, when applied at the set, or ultimately individual value, level will not change, but there will be progressively more towards the RRRR end of the scale. This means that many individual values are only known from 1 or 2 copies.
|Rating||Meaning||Likelihood of finding one|
|CC||Very Common, over 1000 examples known||A certainty|
|C||Fairly Common, less than 1000 examples known||Very likely|
|R||Scarce, less than 200 examples known||Occasionally met with|
|RR||Rare, less than 50 examples known||A pleasant surprise|
|RRR||Very Rare, less than 10 examples known||Make my day!|
|RRRR||Unique, or nearly so, 1 or 2 examples known.||A Red Letter Day!|
©Adam Miller 1997