[coldtea]

The problem the parent describes (reversing as string) has nothing to do with endianess (that would be trivial to overcome). It's not about the byte order in the architecture, wire protocol, or format -- but about how characters are defined and combined from substituent elements in Unicode itself (way beyond the byte order).

[HelloNurse]

Zalgo text provides a straightforward example of how "reversing a string" is ambiguous and ill-defined: one might conceivably want to transpose "letters" along with their respective piles of combining marks, stacked in the same order, not to move combining marks to adjacent letters in a different order.

And of course what characters are a mark-bearing letter is application-dependent and there might be collateral requirements (e.g. if the reversed text is meant to be displayed swapping closing and opening delimiters such as parentheses: "(note)" -> ")eton(" or "(eton)" ).