Yeah, I’ve spent a lot of time with the Codex. It’s very helpful.
I’m running into a strange, and undocumented it seems, problem with custom taxonomies.
I wrote a plugin to define a new content type with its attendant taxonomy. It works, but the taxonomy items do not have the menus in the admin’s left navigation.. If I move the taxonomy definitions out of the plugin and into the functions.php file, then the menus appear.
I can find no documentation in the codex that explains this behavior.