Q: SEO - What element should i use for a heading? For SEO purposes, what tag should I use for my comments heading? The heading tag for the comments contains the Heading of the page with the added word: Comments. Should this be a H2 or H3 or something else? Thanks


A: You should use H2 as H1 is used by Search Engines for Headings in the page.

A: Micro-optimizations and tweaks for SEO purposes are mostly unnecessary nowadays, just make your page semantic to make the search engines interpret it better.
If you used a H1 heading for the title of your article (which I think is the best choice), then use a H2 heading for the comments.

A: The heading tags <h1>, <h2>, create a document outline based not only on their number but also their position relative to sectioning.  That is, <body><h1> is the header for the document.  You can use <h2>, or if comments are in their own <section> you could still use <h1>.  You should not skip headings order (i.e. do not use <h3>).
Note that the lack of <h1>/heading in <section> makes it an untitled section.  You can see how search engines / headless browsers will outline your page using this tool: http://gsnedders.html5.org/outliner/
In summary I would recommend
<h1>Document heading</h1>
<section>
    <h1>Content Heading</h1>
    Content
    <section>
        <h1>Comments Heading</h1>
        Comments
    </section>
</section>

It makes sense to me for comments about the content to be a subsection of the content itself.
