See also the Netscape Navigator HTML Tag Reference:
Block-Level Text Elements
This is an example of the <h1> (header, size 1) tag.
Notice how header text is automatically bolded.
This is an example of the <h2> tag.
Note that ending a header tag inserts the
equivalent of two <br> tags.
This is an example of the <h3> tag.
This is an example of the <h4> tag.
This is an example of the <h5> tag.
This is an example of the <h6> tag.