Where do the tags in Sarn Slums come from?

I believe they are related to the Purity Rebellion, in which Emperor Chitus was overthrown by High Templar Voll, the People's Poet Victario, mayor Ondar of Sarn, and some of their friends. The overturned crown represents rebellion, and the V would be for Voll, who lead the rebellion, or Victario, who seems like he'd be more popular with the people who lived in the slums.