I'll help with
prince post. It's usually added to a king post truss to provide extra support for the bottom chord (tie beam). It's a vertical member, in tension, hung from the connection between the top of the strut and the rafter. The other end connects to the bottom chord.
The main classroom buildings at North House Folk School, in Grand Marais, MN, use these trusses. They were built in the 30's as part of the WPA, I beleive, as USFS buildings. Sorry for the lousy photo, but it's all I could find on short notice:
Notice taht both the kings and princes are steel rods in this example - clearly that would only work if they were tension members.
I think the main reason they used them in this building was to use the attic for storage. The added weight on the tie beams that hold up the bottom chord required additional support.
I've seen the term
queen post applied pretty loosely in a lot of different situations. I do so myself
I call this a queen post bent:
But it's clearly not a truss at all.
Did that help, or just make things worse? CB.