Cardinal letter

The ISO basic Latin alphabet is a Latin-script alphabet and consists of two sets of 26 letters, codified in various national and international standards and used widely in international communication.

The two sets contain the following 26 letters each:

By the 1960s it became apparent to the computer and telecommunications industries in the First World that a non-proprietary method of encoding characters was needed. The International Organization for Standardization (ISO) encapsulated the Latin script in their (ISO/IEC 646) 7-bit character-encoding standard. To achieve widespread acceptance, this encapsulation was based on popular usage. The standard was based on the already published American Standard Code for Information Interchange, better known as ASCII, which included in the character set the 26 × 2 letters of the English alphabet. Later standards issued by the ISO, for example ISO/IEC 8859 (8-bit character encoding) and ISO/IEC 10646 (Unicode Latin), have continued to define the 26 × 2 letters of the English alphabet as the basic Latin script with extensions to handle other letters in other languages.

The Unicode block that contains the alphabet is called "C0 Controls and Basic Latin".

In Unicode 7.0 two subheadings exist:

The letters are also contained in "Halfwidth and Fullwidth Forms" FF00 to FFEF

In ASCII the letters belong to the printable characters and in Unicode since version 1.0 they belong to the block "C0 Controls and Basic Latin". In both cases, as well as in ISO/IEC 646, ISO/IEC 8859 and ISO/IEC 10646 they are occupying the positions in hexadecimal notation 41 to 5A for uppercase and 61 to 7A for lowercase.

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