I think it looks OK. And I am happy to know there was a GOOD reason for the nonsense I saw.
You are the expert on whether it is correct.
As a doc writer, I will ask you this:
Example of Input: array('additional') [additional = ./Themes/default/css/additional.css]
I am not sure what this means. This is not correct array notation.
Perhaps you want it to be array('./Themes/default/css/additional.css') or else you want it to be array['additional'] (where array['additional'] = './Themes/default/css/additional.css')
Or perhaps you want it to be array('additional' => './Themes/default/css/additional.css')
Which is a correct example of EXACTLY what should go in the call?
Or do you really want array ('additional'), because that will cause ./Themes/default/css/additional.css to be loaded?
I am lost.