This is a snapshot of an early working draft and has therefore been superseded by the HTML standard.
This document will not be further updated.
UAs should use the command's Icon as the default generic icon provided
by the user agent when the 'icon' property computes to 'auto' on an
element that either defines a command or refers to one using the
command attribute, but when the property
computes to an actual image, it should use that image instead.