First, I'd like to point out that, in the API page, Tags section, List subsection, it's missing the parameter "type".

Requested feature overview description.
An option to reverse the order of lists received via the API, and possibly the search engines, e.g. tag search.

Why would it be useful?
I reckon it's not needed, it would just make API-wrangling a bit easier.

What part(s) of the site page(s) are affected?
The API and the search engines.

Agreed, I know that with the order parameter it was on track to allow searching by ascending id with id. And apparently you can it seems that that page has not been updated though.

Do you mean that the help page does not list the type? Because I agree that would also be something I would like to see updated. The API help page is outdated in a lot of ways.