It is stated both in prose and in the DTD. From the May 6th, August 4th,
8th and Sept. 22nd drafts (all essentially the same on this point):
Tags delimit elements such as headings, paragraphs, lists,
character highlighting, and links. Most HTML elements are
identified in a document as a start-tag, which gives the element
name and attributes, followed by the content, followed by the
end tag. Start-tags are delimited by `<' and `>'; end tags are
delimited by `</' and `>'. An example is:
<H1>This is a Heading</H1>
Some elements only have a start-tag without an end-tag. For
example, to create a line break, use the `<BR>' tag.
Additionally, the end tags of some other elements, such as
Paragraph (`</P>'), List Item (`</LI>'), Definition Term
(`</DT>'), and Definition Description (`</DD>') elements, may be
This is backed up in the DTD with:
<!ELEMENT LI - O %flow>
<!-- <LI> List item -->
The "-" of "- O" meaning that the <LI> open tag is required, the "O"
meaning the end tag </LI> is optional. I can't claim SGML expertise, but I
must say that it pays to do your homework.
Murray M. Altheim, Information Systems Analyst
National Technology Transfer Center, Wheeling, West Virginia