Ah, partial pedantry. All of Merriam-Webster, the OED, and the Chicago Manual of Style specify that all of BC, AD, CE, and BCE are written in capitals without

Ah, partial pedantry. All of Merriam-Webster, the OED, and the Chicago Manual of Style specify that all of BC, AD, CE, and BCE are written in capitals without punctuation (M-W does list both small caps and punctuation as variants -- the OED only lists small caps).