Digraph (computing)

Digraphs are two-character sequences used to enter single conceptual characters that cannot be entered from the computer keyboard for various reasons: obsolete keyboard, input of special characters is required, the text editor reserves some characters for special use, etc. Digraphs can also be used to extend the keyboard.

Different systems have different sets of defined digraphs.

C programming language supports digraphs in ISO C 94 mode of compiling.
Pascal programming language supports digraphs (., .), (* and *) for [, ], { and } respectively.
Vim text editor uses digraphs.
GNU Screen has a digraph command, bound to ^A ^V by default.
The J programming language uses dot and colon characters to extend the meaning of the basic characters available.
Mobile phones have introduced digraph (and multi-graph) sequences into the English lexicon via Short message service messaging. Emoticons, such as :) appear in modern English language dictionaries.

See also