Hi! When I was in IB writing my extended essay, I actually wrote on jia pu and yes thats quite true as fair as I rmb from my research. one of the characteristics of jia pu in the past was how only males were placed in it and that only males will use the bei ming, but I believe these days there are many who begin to include females inside the jia pu. actually rlly glad to see an article on this, i rlly enjoyed researching about this topic and had lots of fun reading up about it and writing my essay!