User blog comment:Kirkburn/Technical Update: December 2, 2014/@comment-4129195-20141203161743/@comment-5275700-20141203182016

Check out this blog post I wrote about Help pages, a while back.

Short version: Content in the Help namespace on Community Central is shared out (duplicated) in the Help namespace on all other wikias. Individual wikias can add local content to those pages, which will show above the shared content (see w:c:avatar:help:colors for an example of that) or create their own new pages locally in the Help namespace (like the Pokemon example you noted).