I posted previously regarding the TSA PreCheck identifier start to appear on boarding passes if you happen to qualify for the application. And having just checked set for my United flights, I am able to report a slight alter from what the TSA publicised.
Eligible passengers will discover a TSA Pre? ™ warning on all boarding goes over, even when flying because of an airport where TSA Pre? ™ is not really available.
But on Usa, at least, the PreCheck indicator sole appears on my boarding goes over (both mobile and paper) because of departure airports where PreCheck is obtainable.
This isn't anything earth-shattering for any of us in a know, but it should help eliminate confusion for any infrequent, yet PreCheck-approved fliers.