Comment 1 for bug 1281859

On 2014-02-19 02:38 +0100, Cojnel wrote:
> Since the alt modifier key changes the alpha instead of disabling
> changes, then the manual should probably be updated.

Tav's manual documents the current stable version - adjusting the Alpha valua via mouse gesture or scrolling + 'Alt' modifier however is a new feature in trunk (r12822, bug #171890). This is not the time yet to partially rewrite the manual based on changed features in trunk ;-)