There are two main proposals I would like to make. First, have the same number of main reverse die types (for brevity, “R”) for all coins: four die types for all coins. This should simplify the current classification in numista, which has three die types for the One-Peso coin, four types for the 5-Peso coin, and three types for the 10-Peso coin. Second, simplify the identification elements for each type. Identification can be confusing, especially when we get to reverse die type II (R2) until reverse die type IV (R4).
I propose three main criteria for identification, applied in succession:
- Criterion 1. Spacing between the numbers of the date, primarily between the first two digits. Uniform space (narrow) between the numbers, primarily between the fist two digits, can only mean R1. Wider spacing between digits, primarily between the first two digits, can only refer to R2, R3, and R4 (note that R4 has wider space between the the second and third digits, as compared to R3). The first task is to identify if it is R1: if identified as R1 under this Criterion, no need to go through the other main criteria.
- Criterion 2. Distance between the date and the upper/lower elements (inner circle and rim/ribbon). Uniform wide distance between both vertical elements can only be R1 (should no longer be a problem because R1 can be eliminated under Criterion 1). Wide distance towards the inner circle but short distance from the rim/ribbon, can only be R2. Narrow distance to both inner circle and rim/ribbon, can only be R3 or R4.
- Criterion 3. Letter, whether narrow or not (like the difference between “Arial” and “Arial Narrow” fonts). This is particularly material in distinguishing between R3 and R4. Narrow letters, like “Arial Narrow”, can only mean R4 (if not narrow, cannot be R4). The term “narrow” should not be confused with “thin/bold". To illustrate, a “narrow” R4 can either be regular (R4) or bold (R4-bold).
Two secondary criteria: (a) depth of cogwheels; and (b) length of sunrays. In case of conflict between a primary criteria and secondary criteria, the primary criteria prevails (perhaps it should be labelled as a sub-variant).
- Cogwheels. R1 has shallowest cogwheels, R2 has medium cogweels, and R3/R4 has the deepest cogwheels.
- Sunrays. The sunrays are secondary identification elements. Hardly material for 1-Peso, as these coins have uniform sunrays. For 5-Peso, in general, R1 to R3 have longer sunrays, and R4 has shorter sunrays. Most material to 10-Peso, as will be discussed below.
The application of these criteria in identifying die types for 1-Peso and 5-Peso coins is straightforward. However, for the 10-Peso coin, Criteria 1 and 2 can’t be applied, because all are identical. This means that we proceed to Criteria 3 (if narrow, it's R4). If not R4 based on Criteria 3, then we proceed to the secondary criteria listed above. Shallow cogwheels, automatically makes it R1. Deeper cogwheels can only mean R2 or R3 (difficult to distinguish between “medium” and “deeper” cogwheels, unless you have both coins for comparison), so, we go to sunrays: long sunrays refer to R3, shorter sunrays refer to R2.
After going through the main and secondary criteria, subclassifications for each die type can further be made: (a) Bold: normal or bold letters; note that if identification starts with this, an R2-bold may be confused with R3; and (b) Surface finish: regular, frost, frosted, matte or matte-like, proof, etc.
