I tend to agree but the definition seems to depend on the source...JJ
Buckboard bacon differs from traditional American style bacon in that its meat source is typically pork butt, also sometimes referred to as Boston Butt, despite its name does not come from the pig’s butt. Polk butt is a section of the pig that comes from the top part of the shoulder from the front legs.
Additionally, buckboard bacon can be sourced from pork loin as well, which is located just behind the shoulder along the back of the pig. Other areas of the pig can be used to make buckboard bacon, but basically it means any area that is not pork belly, where it is cured and then smoked.
My comment wasn't important enough to have you spend time researching.
All I did was tell what CB & BBB are referring to on this Forum for many years.
CB from Loin----BBB from Pork (Boston) Butt. That was all.
I never even hear of "Polk Butt".
Bear