Optical Character Recognition (Unicode block)

Last updated
Optical Character Recognition
RangeU+2440..U+245F
(32 code points)
Plane BMP
Scripts Common
Symbol setsOCR controls
Assigned11 code points
Unused21 reserved code points
Source standards ISO 2033
Unicode version history
1.0.0 (1991)11 (+11)
Unicode documentation
Code chart ∣ Web page
Note: [1] [2]

Optical Character Recognition is a Unicode block containing signal characters for OCR and MICR standards.

Contents

Block

Optical Character Recognition [1] [2]
Official Unicode Consortium code chart (PDF)
 0123456789ABCDEF
U+244x ⑀ ⑁ ⑂ ⑃ ⑄ ⑅ ⑆ ⑇ ⑈ ⑉ ⑊
U+245x
Notes
1. ^ As of Unicode version 17.0
2. ^ Grey areas indicate non-assigned code points

Subheadings

The Optical Character Recognition block has three informal subheadings (groupings) within its character collection: OCR-A, MICR, and OCR. [3]

OCR-A

A partly redacted German cheque, showing use of , and in the machine-readable line Verrechnungsscheck, WestLB, Landeshauptkasse Dusseldorf, 2004.jpg
A partly redacted German cheque, showing use of ⑂, ⑀ and ⑁ in the machine-readable line

The OCR-A subheading contains six characters taken from the OCR-A font described in the ISO 1073-1:1976 standard: U+2440⑀OCR HOOK, U+2441⑁OCR CHAIR, U+2442⑂OCR FORK, U+2443⑃OCR INVERTED FORK, U+2444⑄OCR BELT BUCKLE, and U+2445⑅OCR BOW TIE. The OCR bow tie is given the informative alias "unique asterisk".

The hook, chair and fork, in addition to a long vertical bar, are included in the most basic "numeric" implementation level of OCR-A, which includes digits but excludes letters and conventional punctuation. [4] By contrast, the most basic implementation level of OCR-B instead includes the digits, plus sign, less-than sign, greater-than sign, long vertical bar and seven of the capital letters; [5] as such, there are no characters specific to OCR-B in the Optical Character Recognition block.

MICR

A cheque signed by Richard Nixon, showing use of , , and in the machine-readable line NIXON, Richard M (signed check).jpg
A cheque signed by Richard Nixon, showing use of ⑆, ⑇, ⑈ and ⑉ in the machine-readable line

The MICR subheading contains four punctuation characters for bank cheque identifiers, taken from the magnetic ink character recognition E-13B font (codified in the ISO 1004:1995 standard): U+2446⑆OCR BRANCH BANK IDENTIFICATION, U+2447⑇OCR AMOUNT OF CHECK, U+2448⑈OCR DASH, and U+2449⑉OCR CUSTOMER ACCOUNT NUMBER.

The latter two characters are misnamed: their names were inadvertently switched when they were named in the 1993 (first) edition of ISO/IEC 10646, [6] a mistake which had been present since Unicode 1.0.0. [7] Although their formal names remain unchanged due to the Unicode stability policy, they both have corrected normative aliases: U+2448 ⑈ is MICR ON US SYMBOL, and U+2449 ⑉ is MICR DASH SYMBOL [8] (the standard notes that "the Unicode character names include several misnomers").

These symbols had previously been encoded by the ISO-IR-98 encoding defined by ISO 2033:1983, in which they were simply named SYMBOL ONE through SYMBOL FOUR. [9] All four characters have informative aliases in the Unicode charts: "transit", "amount", "on us", and "dash" respectively.

OCR

The OCR subheading consists of a single character: U+244A⑊OCR DOUBLE BACKSLASH.

History

The following Unicode-related documents record the purpose and process of defining specific characters in the Optical Character Recognition block:

References

  1. ↑ "Unicode character database". The Unicode Standard. Retrieved 2023-07-26.
  2. ↑ "Enumerated Versions of The Unicode Standard". The Unicode Standard. Retrieved 2023-07-26.
  3. ↑ "Unicode Code Charts: Optical Character Recognition" (PDF). The Unicode Standard, Version 6.3. Retrieved 27 February 2014.
  4. ↑ European Computer Manufacturers Association (1977). "Nominal Character Dimensions of the Numeric OCR-A Font" (PDF) (2nd ed.). ECMA-8.
  5. ↑ ISO/IEC JTC1/SC2/WG3 (1998-09-28). "9.1: Subset 1: Minimal alphanumeric subset" (PDF). Proposal for Type 3 Technical Report, TR 15907, Information technology—Revision of OCR-B standard (ISO 1073-2:1976). p. 8. ISO/IEC JTC1/SC2/WG3 N470.{{cite web}}: CS1 maint: numeric names: authors list (link)
  6. ↑ ISO/IEC JTC 1/SC 2/WG 2 (2012-01-03). "T.3. Optical Character Recognition". Unconfirmed minutes of WG 2 meeting 58 (PDF). p. 29. SC2 N4188 / WG2 N4103. These Magnetic Ink Character Recognition (MICR) symbols are used by banks on checks. The names of these characters were inadvertently mixed up in the 1993 edition of ISO/IEC 10646.{{citation}}: CS1 maint: numeric names: authors list (link)
  7. ↑ "3.8: Block-by-Block Charts" (PDF). The Unicode Standard. version 1.0. Unicode Consortium.
  8. ↑ Freytag, Asmus; McGowan, Rick; Whistler, Ken (2017-04-10). Known Anomalies in Unicode Character Names (4 ed.). Unicode Consortium. Unicode Technical Note #27.
  9. ↑ ISO/TC97/SC2 (1985-08-01). ISO-IR-98: E13B Graphic Character Set (PDF). ITSCJ/IPSJ.{{citation}}: CS1 maint: numeric names: authors list (link)
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