Editing Undocumented feature (section)

{{Short description|Aspect of computer hardware or software}}
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An '''undocumented feature''' is an unintended or undocumented hardware operation, for example an [[undocumented instruction]], or [[software feature]] found in [[computer hardware]] and [[software]] that is considered beneficial or useful. Sometimes the [[documentation]] is omitted through oversight, but undocumented features are sometimes not intended for use by [[end users]], but left available for use by the vendor for [[help desk|software support]] and development. Also, some unintended operation of hardware or software that ends up being of utility to users is simply a [[bug (engineering)|bug]], flaw or quirk.

Since the suppliers of the software usually consider the [[software documentation]] to constitute a contract for the behavior of the software, undocumented features are generally left unsupported and may be removed or changed at will and without notice to the users.

{{anchor|NOMAS}}Undocumented or unsupported features are sometimes also called "not manufacturer supported" (NOMAS), a term coined by ''[[PPC Journal]]'' in the early 1980s.<ref name="PPC_1983"/><ref name="Zenrom_1984"/><ref name="PPC_1985"/><ref name="Wright_2023"/>
Some user-reported defects are viewed by [[software developer]]s as working as expected, leading to the catchphrase "[[it's not a bug, it's a feature]]" (INABIAF) and its variations.<ref name="Carr_2018"/>