Curly brackets with drop shadow. Used as the logo for <a href="https://en.wikipedia.org/wiki/WikiProject_Templates" class="extiw" title="w:WikiProject Templates">WikiProject Templates</a> on English Wikipedia.
<a href="//commons.wikimedia.org/wiki/User:TigerTj%C3%A4der" title="User:TigerTjäder">TigerTjäder</a>
<span class="int-own-work" lang="en">Own work</span>