Circle on 4 or more nodes.
<a href="//commons.wikimedia.org/w/index.php?title=User:0g1o2i3k4e5n6&amp;action=edit&amp;redlink=1" class="new" title="User:0g1o2i3k4e5n6 (page does not exist)">0g1o2i3k4e5n6</a>
<span class="int-own-work" lang="en">Own work</span>