When I was buying my Colt M4A1 SOCOM Carbine with the "Property of U.S. GOVT." marking, I and others noticed that there were two different types of markings: (1) a new engraved marking and (2) the more traditional rollmark marking. Someone else on arfcom had uploaded the difference:
where the top image shows the engraved marking and the bottom image shows the rollmark. I guess it's just personal preference, but I think the rollmarks look better than the engraving. Probably because of the more consistent font and line weight.
Anyway, I read that Colt was moving away from rollmarks and toward engraving for the rest of their rifles. A image taken of the Colt M5 CARBINE from the 2020 Shot Show shows the new engraving:
Today, I was browsing GB and I found a listing of a newer production 6920 with a "M4 CARBINE" engraving:
So, it seems they are out of their rollmarked lowers and will sell engraved lowers from now on. I thought maybe some of y'all might find this pretty much useless info interesting as I do.