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Sub Secondary Classification of Fingerprints: Rules, Calculation & Example

Sub Secondary Classification of Fingerprints

Sub Secondary Classification is a subdivision in the Henry fingerprint system whose values are represented by symbols based on the ridge tracing and counting values of whorls and loops pattern. Index, middle, and ring finger values are used to classify this division.

In this short post, you’re going to get to know what are the rules of using this division along with how to calculate it even in the case of amputated and scarred fingers.

Rules of Using Sub Secondary Division

  • Fingers Used: Index, Middle, and Ring finger
  • Numerator: Right Index, Middle, Ring (finger number 2, 3, 4)
  • Denominator: Left Index, Middle, and Ring (finger number 7, 8, 9)
  • Position in classifying line: immediately after secondary classification
  • Patterns: Loops and Whorls
  • Values: Ridge tracing and Ridge counting
    • Ridge counting for loops
    • Ridge Tracing for whorls

Sub Secondary Classification is Not Used in:

1. Arches: Plain and tented arches on the index, middle, and ring finger.
2. Small Letter Grouping: Henry’s classification number uses small letter groups with secondary classification values. 

Values for Sub Secondary Classification

While filling the card, the value of ridge count and traces are indicated in the corresponding letter. 

A. Letter Designation for Ridge Counting for Loops

FingersLoops Count Symbol
Index finger• Inner (I) = 1 to 9
• Outer (O) = 10 or more
Middle finger• Inner (I) = 1 to 10
• Outer (O) = 11 or more
Ring finger• Inner (I) = 1 to 13
• Outer (O) = 14 or more

B. Letter Designation for Ridge Tracing of Whorls

The ridge tracing is always considered with respect to the right delta. Following are the values for index, middle and ring finger:

  • Meet (M) = 0, 1, or 2 ridges inside or outside the right delta
  • Inner (I) = 3 or more inside the right delta
  • Outer (O) = 3 or more outside the right delta

How to Calculate Sub Secondary Classification Number?

Let’s take an example and understand how you can come up with the sub-secondary division number.

Step 1: Identifying Patterns 

How to Calculate Sub Secondary Classification Number

The following is the visual representation of the various patterns along with their respective ridge counting and tracing values (/ and \ dashes are used for the ulnar loops, w.r.t hands). You can check the dedicated post on how you can fill 10-digit cards (with rules).

  • Index finger:
    • RI = Whorl
    • LI = Radial loop
  • Middle finger
    • RM = Ulnar loop
    • LM = Whorl
  • Ring finger:
    • RR = Ulnar loop
    • LR = Whorl

Step 2: Calculating Ridge Tracing and Counting

  • Index finger
    • RI = 2, outside the right delta
    • LI = 15
  • Middle finger
    • RM = 14
    • LM = 2, inside the right delta
  • Ring finger
    • RR = 16
    • LR = 3, inside the right delta

Step 3: Respective SubSecondary Classification Symbol

  • Index finger
    • RI Value = 2= M (whorl, M= 0,1,2)
    • LI Value = 15= O (loop, O= 9+)
  • Middle finger
    • RM Value = 14 = O (loop, O=10+)
    • LM Value = 2 = M (whorl, M= 0,1,2)
  • Ring finger
    • RR Value = 16 = O (loop, O=13+)
    • LR Value = 3= I (whorl, I= 3 or more inside the right delta)

Step 4: Representing in Henry Fingerprint System

  • Numerator: MOO
  • Denominator: OMI

The following is the Henry number for this 10-digit card.

sub secondary in henry classification of fingerprint

Sub Secondary Classification in Amputated & Scarred Documents

A. Scarred Fingerprints

The following table sets the rule for sub secondary division in the case of scarred fingerprints.

Possible RuleValues
Rule 1: Fully Disfigured ImpressionsPatterns from corresponding opposite finger
Rule 2: Partially scarred with possible known pattern but inconclusive ridge count/trace• If the same general pattern on opposite finger: Ridge count/trace value of opposite finger.
• If different general patterns: probable count/trace value assigned.
Rule 3: Partially scarred with inconclusive pattern (whorl/loop) but possible ridge count/traceRidge counting/tracing of partially scarred fingerprints with the opposite thumb pattern type
Rule 4: Both Corresponding Opposite Finger are fully disfiguredWhorls pattern with meet trace value
Rule 5: Bandaged printsPrints are taken after healing

B. Amputated Fingers

Following table states the possibility of finding sub secondary values in amputated fingers.

Possible RuleValues
Rule 1: 1, 2, 3, or 4 Amputated FingersPatterns from corresponding opposite fingers
Rule 2: Two Opposite Finger are AmputatedWhorls with meet trace value
Rule 3: All fingers are AmputatedMMM / MMM
Rule 4: Both Hands are AmputatedFootprints are used

Practical Worksheet for Sub Secondary Classification

Three practice worksheets are included. For simplicity, I drove out 10-digit card values in form of a table. You can do this too. Check my other post on how to extract data from a 10-digit card and present it in form of a table.

Practice Set #1

Worksheet number 1 for Sub Secondary Classification
*Simple representation for more understanding [1]

Step 1: Identifying Patterns 

 Index FingerMiddle FingerRing Finger
Right HandUlnar loopRadial loopUlnar loop
Left HandRadial loopWhorlUlnar loop

Step 2: Calculating Ridge Tracing and Counting

 Index FingerMiddle FingerRing Finger
Right HandUlnar= 10 countsRadial= 16 countsUlnar= 9 counts
Left HandRadial= 8 countsWhorl= 4, outsideUlnar= 10 counts
*Note: In the case of whorl trace, the values are always with respect to outside or inside of the right delta.

Step 3: Respective SubSecondary Value

  • Index finger
    • RI Value = 10= O (loop, O= 10 or more)
    • LI Value = 8= I (loop, I= 1 to 10)
  • Middle finger
    • RM Value = 16= O (loop, O=11 or more)
    • LM Value = 4= O (whorl, O= 3 or more for right delta)
  • Ring finger
    • RR Value = 9= I (loop, I=1 to 13)
    • LR Value = 10= I (loop, I= 1 to 13)

Step 4: Representing in Henry Fingerprint System

  • Numerator: OOI
  • Denominator: IOI

Practice Set #2

Practice Set #2 for sub secondary
*Simple representation for more understanding [1]

Step 1: Identifying Patterns 

 Index FingerMiddle FingerRing Finger
Right HandUlnar loopRadial loopUlnar loop
Left HandWhorlWhorlUlnar loop

Step 2: Calculating Ridge Tracing and Counting

 Index FingerMiddle FingerRing Finger
Right HandUlnar= 11Radial= 10Ulnar= 13
Left HandWhorl= 3, insideWhorl= 3, outsideUlnar= 16

Step 3: Respective SubSecondary Value

  • Index finger
    • RI Value = 11= O (loop, O= 9+)
    • LI Value = 3= I (whorl, I= 3 or more inside of right delta)
  • Middle finger
    • RM Value = 10= I (loop, I= 1 to 10)
    • LM Value = 4= O (whorl, O= 3 or more outside of right delta)
  • Ring finger
    • RR Value = 13= I (loop, I=1 to 13)
    • LR Value = 16= O (loop, O= 13+)

Step 4: Representing in Henry Fingerprint System

  • Numerator: OII
  • Denominator: IOO

Practice Set # 3: Amputated Finger

sub secondary classification in amputated fingers

Step 1: Identifying Patterns 

 Index FingerMiddle FingerRing Finger
Right HandWhorlWhorlUlnar loop
Left HandAmputatedUlnar loopUlnar loop

Step 2: Calculating Ridge Tracing and Counting

 Index FingerMiddle FingerRing Finger
Right HandWhorl= 4, outsideWhorl= 3, insideUlnar= 9 counts
Left Hand*Whorl= 4, outsideUlnar= 11 countsUlnar= 14 counts
*In the case of an amputated finger, the same values are assigned to the corresponding opposite finger.

Step 3: Respective SubSecondary Value

  • Index finger
    • RI Value = 4= O (whorl, O= 3 or more outside of right delta)
    • LI Value = 4= O (whorl, O= 3 or more outside of right delta)
  • Middle finger
    • RM Value = 3= I (whorl, I= 3 or more inside of right delts)
    • LM Value = 11= O (loop, O= 11 or more)
  • Ring finger
    • RR Value = 9= I (loop, I=1 to 13)
    • LR Value = 14= O (loop, O= 14 or more)

Step 4: Representing in Henry Fingerprint System

  • Numerator: OII
  • Denominator: OOO

Frequently Asked Question

1. What are the fingers included in the sub secondary classification?

Right Index (finger #2), right middle (finger #3), right ring (finger #4), left index (finger #7), left middle (finger #8) and left ring (finger#9) are included in sub seconday classification of fingerprnts.

2. How to obtain sub secondary classification?

Values of sub secondary division are computed based on the ridge trace or counts of whorls and loops in the index, middle and ring finger of both hands. Based on the trace and counts values respective symbols are allocated to obtain sub secondary values.

3. What is the difference between secondary and sub secondary classification?

Sub secondary and secondary classification are subdivisions of Henry classification. Moreover, the values of secondary classification are given by the patterns on the index fingers. While, for sub secondary, the values are in form of symbols of ridge trace and counts and include an index, middle, and ring fingers.

4. If the loop pattern is located in the middle finger and it has 10 ridge counts, how shall we write this in the sub secondary division?

If the middle finger has a ridge count value of 10, it is represented by the symbol ‘I’ (inner). However, if the middle finger value is more than 10, it is represented by the symbol ‘O’ (outer)

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