Red dot sticker with RT punched in the center?

[grantprix]

Wanted to ask the Olds experts here if they've ever seen a factory applied sticker like this before? It's interesting being that it's punched "RT" in the center. This is present on a low mileage '71 Cutlass Supreme that I recently acquired. This car is a very early build (08C) from the Fremont, CA plant and was originally shipped to Olds Motor Division in Denver, CO. I posted this on an Olds Facebook group and one gentleman said it was an inspection sticker with the inspector's initials. Would like to know of another example if anyone has seen this before. Thanks!