The Listing element displays all characters "As-Is" in
the browser as a fixed-width font. Recommended display of this
element is a 132 character line length. Until a closing LISTING tag
is encountered, other HTML elements are displayed on screen as text
and not evaluated.
The rules for this sort of behavior can have many consequences in
parsing techniques, thus the use of this element is strongly
discouraged (the Pre element should be used instead.) This
element (as well as the XMP element) is no longer standard HTML. They
are considered "obsolete" in HTML specifications beginning
with 2.0, but they should be implemented by browsers for backward
compatibility.
