I'd expect both code and name to be subject to deliberate changes (e.g. name "A" is extended to "Alpha" after the name column is extended from 1 to 5 characters

I'd expect both code and name to be subject to deliberate changes (e.g. name "A" is extended to "Alpha" after the name column is extended from 1 to 5 characters) or "technical" edits (e.g. due to out of order data entry, code "A1" should become "A2" in order to insert the proper A1 record). Anything the user sees is a commitment.