gallery.accords-library.com/client/html/help_comments.tpl

<p>Comments support Markdown syntax, extended by some handy tags:</p>

<table>
    <tbody>
        <tr>
            <td><code>@426</code></td>
            <td>links to post number 426</td>
        </tr>
        <tr>
            <td><code>#Dragon_Ball</code></td>
            <td>links to tag &ldquo;Dragon_Ball&rdquo;</td>
        </tr>
        <tr>
            <td><code>+Pirate</code></td>
            <td>links to user &ldquo;Pirate&rdquo;</td>
        </tr>
        <tr>
            <td><code>~~new~~</code></td>
            <td>adds strike-through</td>
        </tr>
        <tr>
            <td><code>[spoiler]Lelouch survives[/spoiler]</td>
            <td>marks text as spoiler and hides it</td>
        </tr>
        <tr>
            <td><code>[sjis](´･ω･`)[/sjis]</td>
            <td>adds SJIS art</td>
        </tr>
    </tbody>
</table>

<p>You can also specify the size of embedded images like this:</p>

<ul>
<li><code>![alt](href =WIDTHx "title")</code></li>
<li><code>![alt](href =xHEIGHT "title")</code></li>
<li><code>![alt](href =WIDTHxHEIGHT "title")</code></li>
</ul>