Check-signing authority is a telltale sign of responsible personhood, unless it is not exercised.

FORBES: Why Spouses Make Lousy Business Partners

He said that the persistently high unemployment rate is a telltale sign of a recession.

FORBES: The Fed Juices Up Gold

This fluorescence is a telltale sign of which atoms are present and a rough idea of how many there are.

BBC: 'Patent medicines' study X-rays old-time remedies

That's a telltale sign, we believe, of liquid water.

NPR: Mars Rover Marks Second Anniversary of Landing

An international research team of cardiologists, radiologists and archeologists used CT scanners to evaluate the mummies, hunting for deposits of calcium in arterial walls that are a telltale sign of hardening of the arteries that can lead to heart attacks and strokes.

WSJ: Telltale Finding on Heart Disease in Mummies