How to Mark Your Doc Number?

[off-the-grid]

The previous owners of my boat just used vinyl lettering inside one of the aft cabins. I was thinking this may not be permanent enough, I was either going to get some sort of plaque made or maybe just epoxy a sheet of clear acrylic over the number.

Now someone is telling that the vinyl numbers are fine. I guess vinyl would technically/potentially leave some "scaring" as the USCG website says, since you'd possibly need to us a blade to remove it, and may leave some glue/ghosting behind, plus maybe some small scratches/nicks from the blade.

I know what it says on the USCG website, but in the real world what is acceptable?