Editing Alt key (section)

{{short description|Computer key}}
{{more citations needed|date=January 2008}}
[[File:Alt - Lenovo.jpg|thumb|The '''Alt''' key  on a Lenovo laptop keyboard]]
[[File:ISO 7000 - Ref-No 2105.svg|thumb|upright=0.6|ISO keyboard symbol for “Alternate”]]
The '''Alt key''' {{keypress|Alt}} (pronounced {{IPAc-en|ɔː|l|t}} {{respell|AWLT}} or {{IPAc-en|ʌ|l|t}} {{respell|ULT}}) on a computer keyboard is used to change (alternate) the function of other pressed keys. Thus, the Alt key is a [[modifier key]], used in a similar fashion to the [[Shift key]]. For example, simply pressing ''A'' will type the letter 'a', but holding down the Alt key while pressing ''A'' will cause the [[computer]] to perform an {{key press|Alt|A}} function, which varies from [[Computer program|program]] to program. The international standard [[ISO/IEC 9995]]-2 calls it ''Alternate key''. The key is located on either side of the [[space bar]], but in non-US PC keyboard layouts, rather than a second Alt key, there is an '[[AltGr key|Alt Gr]]' key to the right of the space bar. Both placements are in accordance with ISO/IEC 9995-2.  With some [[keyboard mapping]]s (such as [[US-International]]), the right Alt key can be reconfigured to function as an [[AltGr]] key although not engraved as such.

The standardized keyboard symbol for the Alt key, {{keypress|⎇}} (which may be used when the usual Latin lettering "Alt" is not preferred for labeling the key) is given in [[ISO/IEC 9995]]-7 as symbol 25, and in ISO 7000 ''"Graphical symbols for use on equipment"'' as symbol ISO-7000-2105. This symbol is encoded in [[Unicode]] as {{unichar|2387|alternative key symbol}}. [[Mac (computer)|Macintosh]] keyboards equate the Alt key with the {{key top|Option}} key, which has its own symbol, similar to that of the ISO standard.

The Alt key should not be confused with the Altmode key (sometimes also labelled Alt) on some Teletype and ASCII terminals, which is a synonym for the [[Escape character#ASCII escape character|ASCII escape character]].