Like 'categories', I want 'pages' to prepend "category/" to their slug; this is because the menu structure was planned to be straightforward ('page' > 'category' > 'post'). Now that that structure is set up, I need the permalinks to reflect the old structure ('category' > 'subcategory' > 'post').
I thought the best way to do this was to just put the slash in the slug, or in other words "category/page-slug". However, when I did that it automatically corrected to be "category-page-slug".
I checked the documentation for slugs and permalinks. It said that the "base" is specific to the taxonomy. When going to Admin > Settings > Permalinks, there is a 'category' base and a 'tag' base, but no 'page' base. I would settle for pages going to "category/" and categories going to "subcategory/".
I also tried using the Custom Permalinks plugin, but after setting each page's slug to "category/page-name", I got 404s; I believe the plugin is still under development and may not be compatible with the newest version of WordPress.
Is there a way to prepend "category/" to the slug of all pages? (I would even convert existing 'pages' to 'categories'!)
EDIT The Permalink Editor plugin worked great for me.