The elements H1, H2, H3, H4, H5 and H6 are used to create several levels of headers, with H1 as the most important header and H6 as the least important.

<!ELEMENT H1  - - (%inline;)* -- heading -->
<!ATTLIST H1
  %attrs;                              -- %coreattrs, %i18n, %events --
  >

Core attributes: class id style title
Internationalization attributes: dir lang
Events: onclick ondblclick onmousedown onmouseup onmouseover onmousemove onmouseout onkeypress onkeydown onkeyup

Value	Description
CENTER	Center the heading in the middle of the line.
LEFT	Put the heading on the left side of the document. This is the default.
RIGHT	Put the heading on the right side of the document.

<H1 align="center">Level 1 header</H1> <H2 align="left">Level 2 header</H2> <H3 align="right">Level 3 header</H3> <H4>Level 4 header</H4> <H5>Level 5 header</H5> <H6>Level 6 header</H6>

Level 1 header Level 2 header Level 3 header Level 4 header Level 5 header Level 6 header