On 22 October 2026 I asked a clinical-trial registry for studies with a start date in 2030 or later. I expected few, maybe none. The server did not say no. It reported 28,888 matches. Then I asked the opposite: studies that started before 1900. The right answer to that one is zero. It reported the same 28,888. That is every record with a submission date, which I take to be the whole registry that day.

Think of asking a librarian for books published in 2030 or later. She answers, "Yes, we have 28,888 of those." The number is not zero, and it is not true. No error. No warning. Just a wrong answer that looks like an answer.

So I now ask a question first whose right answer I already know. If the server gives another answer, the filter is not working. This one was not. A different filter on the same registry passed. It filters on the date a record was submitted.…