What I recommend is to get familiar with the major forum / message board packages as an end user. Seeing as you're posting here, you are probably already familiar with at least one or two of them. I've noticed that they generally use a type of pseudo-HTML written with brackets instead of <tags>. It takes a little acclimatization, but after a short while the tags are as natural as HTML.

I suggest using this system because:
  1. It works.
  2. Your users will probably already be familiar with a similar system.
  3. You will have complete control over the tags, including the ability to create custom tags that combine multiple HTML elements.
Here are some examples of existing systems:

In reply to Re: Pondering Portals by kwaping
in thread Pondering Portals by hacker

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.