Is a medallic strike a variety or an error?

There is an example of the 1894 two cent piece with a 180 degree rotated reverse as well as a 1903 Proof Liberty Nickel. Since there are many of these examples known, are they really errors or should they be considered a variety?
Collector and Researcher of Liberty Head Nickels. ANA LM-6053
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Comments
On Darkside coins, that isn't necessarily the case. Many countries use medallic rotation.
Not that I could answer it any better. It's a good question- what's a "variety" and what's an "error".
Like a tomato.....technically, a fruit....but everyone will treat it like a vegatable.
Currently these are considered errors but they do have some things in common with varieties. They
are repeatable and affect the dies.
Most dies will settle at 180 degree rotation if they come loose and are allowed to rotate.