An EMPTY element must have a start tag and must not have an end tag. Therefore, it is inappropriate to specify an omissible start tag or an inomissible end tag in its declaration.

#0089   Markup Warning

ISO 8879, 11.2.2

An EMPTY element must have a start tag and must not have an end tag. Therefore, it is inappropriate to specify an omissible start tag or an inomissible end tag in its declaration.