Is permission required for creating a derivative?

I wanted to create an Ubuntu derivative and distribute it.

I have read this post. It says no permission is required for creating a derivative and using it.

But if it is given to organizations under a separate name (saying it is a derivative of ubuntu), does this not require permission from Ubuntu or Canonical?

If not, when is permission required for creating and distributing a derivative?

Will availing permission mean that it is a recognized derivative?