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
FF21 Ａ FULLWIDTH LATIN CAPITAL LETTER A FF41 ａ FULLWIDTH LATIN SMALL LETTER A
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.
All of the lowercase letters are used in the International Phonetic Alphabet (IPA). In X-SAMPA and SAMPA these letters have the same sound value as in IPA. In Kirshenbaum they have the same value except for the letter r.
The list below only includes alphabets that lack:
|alphabet||diacritic||multigraphs (not constituting distinct letters)||ligatures|
|Afrikaans alphabet||á, é, è, ê, ë, í, î, ï, ó, ô, ú, û, ý|
|Catalan alphabet||à, é, è, í, ï, ó, ò, ú, ü, ç|
|Dutch alphabet[dubious ]||ä, é, è, ë, ï, ö, ü||The digraph ⟨ij⟩ is sometimes considered to be a separate letter. When that is the case, it usually replaces or is intermixed with ⟨y⟩.|
|English alphabet||-none-||sh, ch, ea, ou, th, ph, ng, zh||æ, œ|
|French alphabet||à, â, ç, é, è, ê, ë, î, ï, ô, ù, û, ü, ÿ||⟨ai⟩, ⟨au⟩, ⟨ei⟩, ⟨eu⟩, ⟨oi⟩, ⟨ou⟩, ⟨eau⟩, ⟨ch⟩, ⟨ph⟩, ⟨gn⟩, ⟨an⟩, ⟨am⟩, ⟨en⟩, ⟨em⟩, ⟨in⟩, ⟨im⟩, ⟨on⟩, ⟨om⟩, ⟨un⟩, ⟨um⟩, ⟨yn⟩, ⟨ym⟩, ⟨ain⟩, ⟨aim⟩, ⟨ein⟩, ⟨oin⟩, ⟨aî⟩, ⟨eî⟩||æ, œ|
|German alphabet||ä, ö, ü||⟨sch⟩, ⟨qu⟩, ⟨ch⟩, ⟨ph⟩, ⟨ng⟩, ⟨ie⟩, ⟨ck⟩, ⟨ei⟩, ⟨eu⟩, ⟨äu⟩||ß|
|Italian alphabet||à, è, é, ì, ò, ù||⟨ch⟩, ⟨ci⟩, ⟨gh⟩, ⟨gi⟩, ⟨gl⟩, ⟨gli⟩, ⟨gn⟩, ⟨sc⟩, ⟨sc⟩|
|Ido alphabet||-none-||⟨qu⟩, ⟨ch⟩, ⟨sh⟩||-none-|
|Indonesian alphabet||-none-||⟨kh⟩, ⟨ng⟩, ⟨ny⟩, ⟨sy⟩|
|Luxembourgish alphabet||ä, é, ë|
|Malay alphabet||-none-||⟨gh⟩, ⟨kh⟩, ⟨ng⟩, ⟨ny⟩, ⟨sy⟩||-none-|
|Portuguese alphabet||ã, õ, á, é, í, ó, ú, â, ê, ô, à, ç||⟨ch⟩, ⟨lh⟩, ⟨nh⟩, ⟨rr⟩, ⟨ss⟩, ⟨am⟩, ⟨em⟩, ⟨im⟩, ⟨om⟩, ⟨um⟩, ⟨ãe⟩, ⟨ão⟩, ⟨õe⟩||-none-|
Note for Portuguese: k, w and y were part of the alphabet until several spelling reforms during the 20th century, the aim of which was to change the etymological Portuguese spelling into an easier phonetic spelling. These letters were replaced by other letters having the same sound: thus psychologia became psicologia, kioske became quiosque, martyr became mártir, etc. Nowadays k, w, and y are only found in foreign words and their derived terms and in scientific abbreviations (e.g. km, byronismo). These letters are considered part of the alphabet again following the 1990 Portuguese Language Orthographic Agreement, which came into effect on January 1, 2009, in Brazil. See Reforms of Portuguese orthography.
The Roman (Latin) alphabet is commonly used for column numbering in a table or chart. This avoids confusion with row numbers using Arabic numerals. For example, a 3-by-3 table would contain Columns A, B, and C, set against Rows 1, 2, and 3. If more columns are needed beyond Z (normally the final letter of the alphabet), the column immediately after Z is AA, followed by AB, and so on. This can be seen by scrolling far to the right in a spreadsheet program such as Microsoft Excel or LibreOffice Calc.
These are double-digit "letters" for table columns, in the same way that 10 through 99 are double-digit numbers. The Greek alphabet has a similar extended form that uses such double-digit letters if necessary, but it is used for chapters of a fraternity as opposed to columns of a table.
Such double-digit letters for bullet points are AA, BB, CC, etc., as opposed to the number-like place value system explained above for table columns.
The Technical Committee TC1 of ECMA met for the first time in December 1960 to prepare standard codes for Input/Output purposes. On April 30, 1965, Standard ECMA-6 was adopted by the General Assembly of ECMA.