[rexf]

What is the precheck card?

From my anecdotal experience, your boarding pass may have TSA precheck mark. This has been sufficient for me to go into the TSA precheck line (vs regular default line).

Also, I usually see a person at the precheck line entrance screening people for boarding passes with the precheck mark. Otherwise they will direct you to the regular line.

[jthrowsitaway]

Some of the smaller airports that I've been through give you a laminated PreCheck card after they've checked your ID and ticket. You hold onto that for a few seconds until you're called up for the next stage of the process. The officer takes the card, places a PreCheck indicator on the belt alongside your luggage, then un-ropes the metal detector and waves you through. Large airports have dedicated lines for PreCheck and don't require all this.

[lights0123]

For some airports with low amounts of traffic, there isn't a separate precheck line, so you're just given some sort of marker that tells the workers to treat you as a precheck member in the standard line.