Emails keep themselves. Calls, corridor conversations and the thing somebody said on the way out do not, and those are the ones that turn out to matter. A note made the same day is worth something; the same note written six months later, after it became important, is worth almost nothing and everybody in the room knows why. This takes thirty seconds and keeps them in order.
When it was written matters as much as what it says. A note made the same day carries weight. The same words typed six months later, after the thing became important, carry almost none, and everybody reading it knows which one they are looking at. This records both times: when the conversation happened and when you wrote it down, and it tells you when the gap between them is getting long.
Write what was said, not what it meant. "He accepted the delay was ours" is a conclusion. "He said, more than once, that he was not going to argue about whose fault it was at this stage" is a note. The first will be picked apart; the second is just what happened. Where you are quoting, quote; where you are summarising, say so; where you are unsure, write that you are unsure, because that is worth more than false precision.
The promises are the part you will want. Most of the value in a log like this is the column recording what somebody said they would do and by when, and then whether it happened. Each entry here can carry one, and the page keeps the outstanding ones in front of you rather than letting them drift into things everyone has half-forgotten.
Spoken and unwritten is what this is for. Email keeps itself and needs no help. The conversations that never turn into anything written are the ones that decide matters and vanish, so the page counts those separately: how much of this thread exists nowhere except in it.
It stays on this machine. A contemporaneous note is a private working document about a live matter, often naming people who would not enjoy reading it. Keeping one on somebody else's service would be an odd choice. Export it and keep it with the file.
That it was made at or near the time, before the events became contentious. There is no bright line; the question is whether the note was made as part of doing the job or as part of building a case. Writing it the same day and recording that you did is what keeps it on the right side of that.
Usually there is nothing to tell: writing down what happened in a meeting is ordinary practice. Recording a call is a different matter, and in many places doing it without saying so is unlawful. This keeps notes, not recordings.
You can, and the page records that you did and when. Correcting a note is normal and honest; quietly rewriting one is the thing that destroys the value of the whole log. If something turns out to be wrong, add a later entry saying so rather than editing the past.
No, and it is where one comes from. A statement is a formal document with a statement of truth; this is the raw material somebody would use to write it, and the sequence it produces is the shape a statement usually takes. WITNESS is for the statement itself.
Write that. "I cannot remember his exact words but the sense was" is a proper note and reads as an honest one. A note that is precise about everything, six months on, reads as a reconstruction, because it is.