Personal Flag of Queen Sirikit of Thailand. Depicting the Royal Cypher (Thai: ส. ก.) surmounted by the Crown of Victory. On a blue field, the colour of the Queen's Birthday; Friday.
<a href="//commons.wikimedia.org/wiki/User:Sodacan" title="User:Sodacan">Sodacan</a>
CC BY 3.0
Own work by uploader, Based on; <a class="external autonumber" href="https://en.wikipedia.org/wiki/File:Queen_Sirikit_arms.jpg">[1]</a>