How should an answer handle a flaky test without normalizing it?

A Q&A design question about giving practical flaky-test advice without treating quarantine as a permanent fix.

For flaky tests, an answer has to be practical without making “just quarantine it” sound like the final fix. I like answers that ask for failure rate, owner, first failing build, suspected cause, and whether the flake represents customer-visible nondeterminism. What else should be required before quarantine is acceptable?