A named participant, analyst or institution asserts the link on the record.
The definition the product enforces, read from the same code the methodology page renders.
Someone on the record says A caused B, and the page tells you who. Weigh the speaker: a regulator's finding and a rival's press release both land on this rung, and the name beside the link is what separates them. It is attributed, not established.
How a cause-and-effect link is KNOWN, kept apart from how much it matters. A documented link can be weak; a strong link can be inferred.
Every grade here is assigned by the same rules on every scan, and the methodology page renders those rules from the code that enforces them.