SNOMED CT® Release Format 1 (RF1) Guide - ihtsdo

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0
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Table 29: The full array for Function F
0
1
2
3
4
5
6
7
0
0
1
5
8
9
4
2
7
Table 30: The Inverse D5 array
0
0
1
4
1
8
1
1
5
8
9
4
2
7
0
2
3
2
7
2
2
7
0
1
5
8
9
4
3
2
3
6
3
3
6
3
6
3
6
3
6
4
1
4
5
4
4
2
7
0
1
5
8
9
The Identifier is checked by starting at the rightmost digit of the Identifier (the check-digit itself) and proceeding
to the left processing each digit as follows:
• Check = ArrayDihedralD5 (Check, ArrayFunctionF((Position Modulus 8), Digit))
Check = the running value of the check-sum (starts at zero and modified by each step).
Position = the position of the digit (counted from the right starting at zero).
Digit = the value of the digit.
.
The final value of Check should be zero. Otherwise the check has failed.
When calculating the check-digit the same process is applied with a minor variation:
• Position is the position that the digit will have when the check-digit has been appended.
• The final value of Check is applied to the Inverse D5 array to find the correct check-digit.
Check-digit = ArrayInverseD5 (Check).
.
5
5
5
4
5
5
8
9
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7
0
1
6
6
6
3
6
6
3
6
3
6
3
6
3
Structure and Content Guide | 93
© 2002-2012 International Health Terminology Standards Development Organisation CVR #: 30363434
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