When should an old link be kept for history instead of removed?

Asks how to decide between deleting old links and marking them as retired evidence.

A broken or outdated link is easy to delete, but sometimes it explains why a wiki or checklist used to say something different. I usually want to keep it only when it preserves a past claim, a source conflict, or a correction trail. Otherwise it just adds noise. Where do you draw the line between useful history and stale clutter?