Frank, I have a Bernard CH without a vent rib and I've seen others which have the legend on the rib engraved. Perhaps Parker Bros did not have a roll die for Bernard Steel barreled guns.

Most vent rib guns have the rib legend engraved. Parker found that roll marking vent ribs damaged them.

Dean, early Bernard regular ribs were engraved, later ones roll stamped. I have not made enough of a study of them to form an opinion about the year date that the Bernard roll stamp started being used, although it was sometime in the 1890's. Vent ribs were a different matter.