If you’re adding something meaningful to the discussion, we prefer to have topics grouped together rather than 50 different topics all repeating the same information.
Times you should never necro include but are not limited to minor grammar or spelling corrections on a post from 3 years ago.
Times a necro may seem warranted but could possibly be split by a mod include if the information is outdated and a new user was not aware that the system had changed, for instance old posts about our former ELO rating systems before we switched to one glicko rating per user
In short, always ask yourself “am I adding something meaningful to this converstaion” and if so it’s probably fine to necro but if not it’s possibly not a needed comment regardless of how old the post is…