I have found a question where the accepted answer is correct, but out-of-date. A newer answer gives a better solution for more recent versions of the library. I am neither the asker nor the answerer, but I thought it might help people like me if I edit the accepted answer with something along the lines of "Since version xxx, you can do this: [new answer]; The original solution for previous verions is [old answer]", as I have seen done on other questions.
What is the etiquette here? I think it would be valuable to copy the newer answer into the accepted answer (obviously citing the user responsible) but I am also aware the user will not gain reputation for their answer as a result. Or, could I edit the question say something along the lines of "See xxxx's answer below since version xxx"?