Several unofficial extensions exist, though most of them are not currently supported.

Skirmishes between government troops and armed groups lasted until 1913, and some historians consider these unofficial extensions of the war.

The trail also has an unofficial "extension" which continues 2 km straight to its terminus with North Talbot Road.

An unofficial extension known as the International Appalachian Trail continues north into Canada and to the end of the range, where it enters the Atlantic Ocean.

PNG supports animation only via unofficial extensions (see the section on animation, above).

As a result, Progress for America often functions like an unofficial extension of the White House, advancing the president's policies alongside the Republican National Committee.

MPEG-2.5 is thus an unofficial or proprietary extension to the MP3 format.

It was described by the media as "unofficial extension" of the Suraag.

Some historians consider these unofficial extensions to be part of the war.

Additionally, many unofficial extensions have been created by players.