Hi SirThomas - thanks for registering. I like all those pictures you took in North Korea - as a plug, here's the link to your flickr page:
http://www.flickr.com/photos/tpeddle , quite a few nice ones of the lovely
traffic ladies. ( I still want to know who kidnapped the little girl

)
I have been meaning to research the ranks and add it to the PTG info topic, but procrastination rules with me. I'll get moving on it soon now. I think their shoulderboard rank is comparible to the NK army ones, but without as many in-between ranks. (there is no Brigadier General traffic rank for example...I think...).
Eric Martin (his flickr page
HERE used to have a listing of NK ranks, along with lots of trafficgirl info, on his intermoumoute.com website, but it has gone offline for some reason. I have the info saved somewhere, I'll dig it out.
For now what we can see is that the PTG shoulderboard ranking progresses from 1 to 3 vertical bars, and then to the thick double horizontal bars with 1 to 3 stars.
More to come ...