I haven't seen much in the Community regarding the PMBOK Template Documents (apologies if someone has indeed posted something, and I haven't stumbled across it) so I thought I'd offer the attached document into the greater body of knowledge.
I will include more info in future revisions, but the attached gives a general overview of the nine Template Documents available to users once 1) the given users' permissions include access to the PBK documents, and 2) the Project Investment is set with the PBK_Flag to be True. I configured the Project General Settings Section to display the PBK_Flag so that the PM can easily use this field as a toggle.
The main treatment pertains to the various Template Documents, their fields and respective entry type/capacity.
Hope you enjoy.