Generally this may be called typo but when particularly two letters of a word are mistakenly swapped, what is this error called? Some examples:
teh > the
fromat > format
comptuer > computer
That is called a transposition error, and is very common for reasonably speedy touch-typists. The text editor Emacs even has a basic control chord (Ctrl+T) to swap (transpose) the preceding two characters.
From Wikipedia's transcription error page:
This word is most often used of swapping sounds, but the OED defines it as "The transposition of sounds or letters in a word, or (occas.) of whole words or syllables; the result of such a transposition".
I've seen "type twister". In German, there's a term for numbers getting twisted, "Zahlendreher" ...
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