This keeps coming up with transcription work. The question is, when transcribing a person speaking their local dialect, what characters should you use? I provide the following definitions, which are up for debate:
本字 běnzì – The character that most accurately represents the word in etymology. In a way, it shows the cognates.
正字 zhèngzì – The “Standard” character. That which represents the meaning of the intended word for a wider audience.
As a semi-hypothetical example, Dialect X has a word that means “high” or “tall”, read “huan”. It’s cognate with Mandarin 懸 xuán as any educated speaker will tell you. A speaker of Dialect X may write it as 懸, or they may just write 高. They wouldn’t say 高 gāo or a cognate of 高. But then they may assume the rest of the country which doesn’t speak their dialect might not know 懸 as having this meaning, since in Standard Mandarin 懸 means “to hang”. So if you can imagine, they’re still writing in their dialect, but they’ve changed the characters to make it just a little easier to read for a wider audience.