The person working beside you should not have to infer which version of the plan is current.

Plans change in one person’s head, and the update travels slower than the change. Everyone else keeps working from what they last heard, guessing at whether the new remark replaced the old one or sat beside it, and the errors that follow look like carelessness. They are not. They are the cost of asking people to reconstruct the current version from clues.

When something changes, say so plainly and say what it replaces. Keep one place where the current version lives, so nobody has to search a conversation for it. Assume that if two people could reasonably guess differently, they will.