I can't find where UL and LI tags are coming from ?!?

Hello,

I have a weird question : could it be that wordpress self-generates <ul> and <li> tags under certain circumstances ?

It all started with my /myblog.net/2007/ archives page, I noticed it listed first the permalink with the title, and then, in a bulletlist, the categories to which the post belonged.
I thought it was ugly, so I decided to display:inline this bullet list.

However, looking at my archive.php page (I use the andreas-08-3-columns-ver-05 theme, quite old but doing perfectly its job and not sucking up server resources), I only found this, snippets follow :

<?php /* If this is a category archive */ if (is_category()) { ?>
		<h3>Archive for '<?php echo single_cat_title(); ?>'</h3>
(...)
<?php /* If this is a yearly archive */ } elseif (is_year()) { ?>
		<h2 class="pagetitle">Archive for <?php the_time('Y'); ?></h2>
(...)
<?php } ?>
<?php while (have_posts()) : the_post(); ?>
		<a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link a <?php the_title(); ?>"><?php the_title(); ?></a>
		<small><?php the_time('j F Y') ?> <!-- by <?php the_author() ?> --></small>
		<?php the_category() ?>
		<?php endwhile; ?>

Not many <ul> or <li>, is there ?

And yet, when I open my myblog.net/2007/ (or any year) page, and click to see its source code, I’m shown this :

<a href=" (url) " rel="bookmark" title="Permanent Link (title of the post - oops I should fix that somehow)">(title of the post)</a>
<small>(date) <!-- by (user's pseudo) --></small>
<ul class="post-categories">
<li><a href="url to the category" title="View all posts in (name of the category)" rel="category tag">(name of the category)</a></li>
<li><a href="url to the category" title="View all posts in (name of the category)" rel="category tag">(name of the category)</a></li>
<li><a href="url to the category" title="View all posts in (name of the category)" rel="category tag">(name of the category)</a></li>
<li><a href="url to the category" title="View all posts in (name of the category)" rel="category tag">(name of the category)</a></li></ul>

So, I searched ALL of my theme’s php files, and the few <ul> and <li> tag occurences were strictly NOT related to the present case, and could not be used as such (I’m paranoid, I tested removing those occurences to no avail.)

I noticed, this isn’t the same for my regular posts, in the bottom of my regular posts the categories are listed in a single line, without bulletlisting, with this php code calling them :
<span class="filedto">Categories : <?php the_category(', ') ?><br /><?php the_tags() ?></span>

Nothing particular worth mentioning in the CSS style.css either, only assigning margins to ul and li tags.

This leads me to ask : please, could it be that, under certain circumstances, wordpress self-generates HTML tags ?

Or is it impossible, and then that means I simply overlooked something, anything ?

I’m really puzzled, I’ll be grateful if you can be of help… Thank you ! ??