No if you d read the WP MOS it explicitly allows both styles as long as articles are internally consistent What is not allowed is to change an article which consistently uses one style to another style which is what you and have been doing The community has rejected not only using BCE CE as a standard but also BC AD instead preferring to allow both systems The majority vote was to reject the BCE CE as a standard Apparently it is still not settled Wikipedia Manual of Style 28dates and numbers 29 Eras It is interesting to note that YOU have appointed yourself the arbiter of which one to use for consistency Note that I am entitled to do the same and revert you I do suggest that you consider only BC AD for consistency as well but I have not seen you opting for that version in a single article