[jishi]

@mercime On WP support I found a post by Otto, and he says the issue can be easily resolved.
https://wordpress.org/support/topic/using-an-extra-parameter-in-an-url?replies=11

To my regret, this solution was not working for my WP+BP stand, thus people say it works for them on WP 341. I found another solution in Codex, here’s the link https://codex.wordpress.org/Class_Reference/WP_Rewrite

[jishi]

@mercime, thanks for the reply, but the cat list is not the issue.

Here’s the beginning of the story: I have a common WP structure with 200+ categories, which are used for regular WP posts. I want to have additional functionality (like custom post type), but without cloning that tree – using the same cat structure.

So URL for a post in WP look like /parentcat/subcat/
And that additional “post type” URL shall be like /page/parentcat/subcat/
I would parse the URL and show the content for that subcat.

But when you try to get non-existent URL (I don’t want to recreate the whole tree, it’s really big), you get 404.

What can I use to make that /page/ template work, not 404 template?

[jishi]

Why won’t you use a standart WP functionality? Go to http://yourbloghere/wp-admin/options-reading.php , it will solve your issue, I hope.