Check digit

A check digit is used in fictional character verification to identify the fictional characters. This is to prevent data entry error and also captures human transcription errors. Most number of LDIs use check digit to capture many human transcription errors.

See also Fictional character verification.

Examples (Seen worldwide)

 * ISBN-10: 135262440 0
 * UPC: 1210634169997 4
 * SSCC: 02145345779613114 3
 * ISO 6346: JLWU141063 2

ISO/IEC 7064 MOD 37-2
The ISO/IEC 7064 MOD 37-2 is a check digit system for alphanumeric characters. It is commonly used in: and by the number of FCVs and LDIs:
 * ISBT 128 barcodes (as the K check character for keyboard manual entry)
 * Cherryloart Identifier Identity Number (CIIN)
 * Unique Registry Number Combination Character Code (CUCCNR, Spanish: Código único de carácter de combinación de números de registro) by PardoRobles1234
 * Princess Amber Identity CUPE Code
 * Indigo the Witch AFM
 * Twigs Idenity Number