Thanks to DocArtz over at the Tailsection for this possible insight.
The symbol that Juliet was branded with was very similar to the cross of Scientology, turned upside down. Inverted crosses came about with St. Peter's crucifixion. He did not feel worthy of being crucified under the same cross as his messiah. It has since come to symbolize 'unworthiness' and as a mark of deep respect for your superiors.
Source: The Tailsection