I got my first comment yesterday. According to the Etiquette of Blogging, I had to respond. However, my response didn't look any different from the first comment, so there's no way to tell if it was a comment actually from me, or from someone pretending to be me.
I've been working with Symphony for a little while now, so I kind of know where stuff is. First thing I did was check the Symphony database table for any kind of author tracking, and it turns out that Symphony stores the id of the author if they are logged in.
The next thing was to check the Comments data source (Blueprints > Controllers). There's a field called authorised, and Dru over in the Overture forums told me that the authorised field will give you XML that looks like this:
<comment id="199" authorised="yes" author_id="1">
<author>Name</author>
</comment>
So to check for an actual authorization, you'd use
<xsl:if test="@authorised">
To translate this into the Comments template, it's a bit trickier. What Dru recommended was to set the class attribute of the div with XSL, like so:
<xsl:if test="@authorised">
<xsl:attribute name="class">
<xsl:text>comment author</xsl:text>
</xsl:attribute>
</xsl:if>
Place that just below the line that has <div class="comment">, and it will replace the class of comment with comment author when you want to display the author's comments differently. It would make sense to have each author have their own class, but I currently don't need to do that. It wouldn't be too hard, because there's the author_id field in the XML, you'd just need to display that as well.