[tz] Why is `Etc/UCT` not an alias of `Etc/UTC`?

[Guy Harris]

On Mar 5, 2019, at 2:27 PM, Arthur David Olson <arthurdavidolson at gmail.com> wrote:

> A maintenance guess: there would be more complaints about setting TZ to UTC and getting UCT as an abbreviation than there are about UTC and UCT not being links.

What about complaints about setting TZ to UCT and getting UTC as an abbreviation?

Is there any information about whether "UTC" or "UCT" is the more commonly used abbreviation in documents in English?