In individual cases that we have found, turns out that those children most of the time will have had a marker of some type that we stem back and say, ah, that's the autism cause and etiology versus vaccines.

NPR: Pediatrician: What Parents Should Know About Autism

The man had on a headlamp with a tan cotton band, like some dentists wore, and a type of thick black marker in his breast pocket.

NEWYORKER: Wiggle Room

In fact, in interviews to determine personality type, therapists consider short, concise answers to be a marker of an avoidant attachment style.

WSJ: What Makes People Overshare?