Three small dots in a triangular pattern above and below the alignment aid on Pro V1s and Pro V1x. This is a new 2021 Pro V1 shown with black dots. If it were a V1x, the dots would be red. Helps me quickly identify whether V1 or V1x when I grab one out of the ball pocket, without having to look closely. On AVXs, which I play a lot in winter and wind, I also use red sharpie dots, but keep them in a separate pocket. Plus the dimples are completely different looking on AVX, which is immediately identifiable to me. (They look much more like Bridgestone dimples.)
In addition to the dots, when I purchase the 443 special in March or April each year, I usually have them custom printed with my personal 3 line message and the Team Titleist logo. Sorry the two pics of my custom ones below are a bit out of focus.
