So ... the nurse at the check-in desk handed me an electronic passcard labeled 'EATME' ...

I thought it was a peculiar thing to see on a security card. Did they just assign some sort of randomly chosen phrase to each card ? Was there some inscrutable logic behind these labels, like the names of Ships in The Culture ? At first I thought I saw some strange 3D effect as the card was tilted, but that was just some other writing, so completely faded it was only visible from just the right angle. (Only later did I recall that a small cake marked 'EAT ME' had cause a lot of trouble for Alice in Wonderland ...) As I puzzled over this, I noted that the card had lots of wear, from handling by many hands, so that the other markings on the card were worn away almost completely, with the wear being very heavy near the edges, where it was easily grasped, and much less near the center, where the phrase 'EATME' appeared ... and that was when I finally realized that the card had originally been labelled 'TREATMENT'.