Authorship disputes happen at submission, which is the one moment when they cannot be resolved calmly. Everyone has been working for a year on an assumption nobody stated, and the assumptions do not match. In a three-tier lab this is sharper than usual: an REU student who ran the sweeps, an MS student who built the data pipeline, and a PhD student who wrote the paper have genuinely different claims, and none of them are obvious. Writing it down early costs an hour. Not writing it down costs a relationship.
The CRediT taxonomy — fourteen defined contributor roles, and the standard most journals now ask for directly. The ICMJE authorship criteria for the four-part test of what makes someone an author rather than an acknowledgement. Both define terms. Neither resolves your specific case, which is the point of the mechanic.
None.
For a paper you are actually working on:
The statement, plus evidence it was circulated — a timestamp, a thread, a forwarded message.
This replaces your writing entry for the week you do it. Submit it to that week’s WW assignment in Canvas — the same one you would have submitted anyway. It is not an extra piece of work on top of the log.
You do not submit anything to the milestone yet. When all five skills in M4 are done, submit the M4 — The Manuscript assignment, which is just an index saying which week each one went in.