These tags are used for titles and indicate the level of importance of the title and related information. <h1> is the most important and <h6> is the least.
Headings are very important for both 508, and SEO.
Headings are intended for a new section or subsection of the page.
The h1 element must not appear as a descendant of the address element.
<h1> - <h6> can be used in <body>
<h1> - </6> can be used in <header> Its less likely to use lower than <h1> or <h2>
<h1> - <6> can be used i n <main> Its unlikely that you will use lower headings within the main if you are including sections and or articles. <h1>-<6> can be used in <section>
<h1>-<6> can be used in <article>
<h1>-<6> can be used in <aside>
<h1>-<6> can be used in <nav>
<h1>-<6> can be used in <footer>
<h1>-<6> cannot be a descendent of <address>
<h1>-<6>cannot be a descendent of <p>
Whereas headings would be expected to be used in <main>, <section>, <article> and sometimes <header> or <aside> they are less likely to be used in <nav> or <footer>.
Should it stay part of the specification here is how to use it:
The hgroup element is used to group headings together. It must contain at least two of the heading elements and no other information. It is for grouping a title with a subtitle. It can contain different combinations such as <h1> with <h2.> or <h3> with <h4> etc.
For those of you that create headings with display: inline ( to get rid of the unsightly gap) and then add a <br> you will not longer be able to do this because it will not validate if a <br> is inside an hgroup. You need to play with the margins inorder to reduce the gap.
Attributes: All Global