This section lists elements of HTML whose use should be avoided, whether because the element is now obsolete, or because the element is being deprecated (i.e. still supported, but its use is not recommended and the element may eventually become obsolete).
Several elements of HTML are obsolete,
including PLAINTEXT, XMP, LISTING, HPx, and COMMENT. The first three
should be replaced with PRE; HP
(highlighted phrase) should be replaced with the character
highlighting elements; and COMMENT should be replaced with
<!-- blah blah blah -->, the
SGML
comment characters.