What amendment means
An amendment is a change made in a way that keeps the original visible. Instead of deleting what you first wrote and typing something new over it, an amended record shows the first version, the change, and when the change happened. The point is not that you never make corrections; it is that corrections are honest and traceable.
This matters because the single most damaging question a custody record can face is whether it was edited to fit the story. A record that can only show its current state invites that suspicion. A record that shows its full history answers it: yes, an entry was corrected on this date, and here is what it said before.
Example: you log an exchange as happening at 6:00 pm, then realize it was 6:30. Overwriting the time leaves no trace and, if questioned later, looks like tampering. Adding an amendment that notes the correction and its date preserves your credibility precisely because it is transparent.
Good documentation tools timestamp amendments automatically so the history is created for you rather than depending on your discipline.