3 * PostgreSQL type definitions for ISNs (ISBN, ISMN, ISSN, EAN13, UPC)
5 * Information recompiled by Kronuz on November 12, 2004
11 * 1144-875X <=> 1144875(X) <=> 1144875 <=> (977)1144875 <=> 9771144875(00) <=> 977114487500(7) <=> 977-1144-875-00-7
15 * Weight 8 7 6 5 4 3 2
16 * Product 8 + 7 + 24 + 20 + 32 + 21 + 10 = 122
17 * 122 / 11 = 11 remainder 1
18 * Check digit 11 - 1 = 10 = X
21 * ISSN 9 7 7 1 1 4 4 8 7 5 0 0
22 * Weight 1 3 1 3 1 3 1 3 1 3 1 3
23 * Product 9 + 21 + 7 + 3 + 1 + 12 + 4 + 24 + 7 + 15 + 0 + 0 = 103
24 * 103 / 10 = 10 remainder 3
25 * Check digit 10 - 3 = 7
26 * => 977-1144875-00-7 ?? <- suplemental number (number of the week, month, etc.)
27 * ^^ 00 for non-daily publications (01=Monday, 02=Tuesday, ...)
29 * The hyphenation is always in after the four digits of the ISSN code.
33 /* where the digit set begins, and how many of them are in the table */
34 const unsigned ISSN_index
[10][2] = {
46 const char *ISSN_range
[][2] = {
47 {"0000-000", "9999-999"},