| Key | Major | Primary | Secondary | Subsecondary | Final |
| Divisions | Classification | Classification | Classification | ||
| 20 | M | 1 | U | IOI | 10 |
| L | 1 | U | IOI | ||
Key | Major | Primary | Secondary | Second subsecondary classification Subsecondary | Final |
| Divisions | Classification | Classification | Classification | ||
4 | O | 5 | U | SLM ——— MMS IOI | 10 |
| I | 17 | U | IOI |
The primary classification: For the purpose of obtaining the primary classification, numerical values are assigned to each of the ten finger spaces as shown in figure 347. Wherever a whorl appears it assumes the value of the space in which it is found. Spaces in which types of patterns other than whorls are present are disregarded in computing the primary.
The values are assigned as follows:
| Fingers No. 1 and No. 2 | 16 |
| Fingers No. 3 and No. 4 | 8 |
| Fingers No. 5 and No. 6 | 4 |
| Fingers No. 7 and No. 8 | 2 |
| Fingers No. 9 and No. 10 | 1 |
[Fig. 347]
![[Enlarge]](#2873848932677661140_fig347a.jpg.id-2001204834867402782.wrap-0.html.html){kind=link}
In figure 347, it will be observed that the odd fingers (Nos. 1, 3, 5, 7, 9) contain the letter D, and the even fingers (Nos. 2, 4, 6, 8, 10) contain the letter N. The D indicates that the values of these fingers relate to the denominator, the N that they relate to the numerator. The summation of the numerical values of the whorl type patterns, if any, appearing in fingers 1, 3, 5, 7, 9, plus one, is the denominator of the primary. The summation of the values of the whorls, if any, in fingers 2, 4, 6, 8, 10, plus one, is the numerator of the primary. Where no whorl appears in a set of impressions, the primary, therefore, would be 1 over 1. The 1 that is assigned to the numerator and the denominator when no whorls appear is also added, for consistency, to the value of the whorls when they do appear. It will be understood why it was originally assigned to the no-whorl group when it is considered how easily a zero might be confused with an O, which is the symbol used for an outer whorl tracing.
To obtain the primary for the prints in figure 347, the number of whorls appearing in the odd fingers is ascertained to be 2. Their positions are noted (1 in No. 1 and 1 in No. 7) and the values assigned to whorls appearing in those fingers are added together (16 plus 2 = 18). To this sum the arbitrary 1 is added, giving us the total of 19, which constitutes the denominator for this set of prints. To get the numerator, it is ascertained that there are 3 whorls appearing in the even fingers (2, 4 and 6), the values of which are added together (16 plus 8 plus 4 = 28). To this sum the 1 is added, giving a numerator of 29, and a complete primary of 29 over 19.
By the word "whorl" is meant all types of whorls, including plain whorls, central pocket loops, double loops and accidentals. The tracing of the whorl does not enter into the determination of the primary.