i think the best you can do is something like mine and give them a role name, do you know how to do that?
How big is the logo? And you would want to put it on the bottom of their large profile pic only?
It would just look like a tiny dot on the smaller avatar so that would not be good, you would only be able to use it on their large avatar.
in ow_plugins/forum/views/controllers/topic_index.html
look for this section and try to put your image right after the avatar which i have marked with a comment line for you
{foreach from=$postList item=post name=postList}
{capture assign='tpl'}{capture name='info_string'}
<a href="{$avatars[$post.userId].url}">{$avatars[$post.userId].title}
</a> <span class="ow_tiny ow_ipc_date ow_remark">{$post.createStamp}</span>
{/capture}
<!-- try putting your image here and see where it shows, dont forget to clear your cache, if that does not work then move this inside the capture above with a <br /> and then your image. -->
{capture name='content'}<div class="post_content">
the <!-- is the open comment and the --> is the close comment everything in the middle is html comment only
i you happen to see that link sorry about the inclusion of the post link before i was saving what i was working on lol i have removed the link lol
so do
<img src="http://www.tibiaevents.com/teamlogo.png" border="0" alt="" />
fire it up and let me know thanks