I was tempted to categorize this as a “Faux NOOB” because the ae combination in such forms as orthopaedics, paediatrics and archaeology derive from ancient Greek and aren’t specifically British. But until a recent pronounced uptick, they have traditionally been found much more commonly in Britain than in the U.S. Thus I feel they represent a proper NOOB.
I do, however, enthusiastically put them in a new category I’ve just created: “Commerce.” That’s because no one (or no American) on his or her own would think to write paediatrician rather than pediatrician. Rather, the ae form in this word and in orthopaedic appears on every billboard and print advertisement I see these days because some ad-person thought they sounded classy, official and vaguely British. (Remind me to retroactively put bespoke and stockist in this category as well.)
A special case is encyclopaedia. According to the OED, that spelling would have become “obsolete” in the late 19th century were it not used by the “Encyclopaedia Britannica” and other reference works. “Britannica,” of course, not only uses the a and e but famously connects them in a fused character called a ligature. Interestingly, while ae is still very much of the operation’s trade name, there appears to be some movement toward losing the a, as in this Google search result:
The only person who pronounces the ae in encyclopaedia is Ted on the sitcom “How I Met Your Mother.” He’s routinely ragged for this by his friends, including Robin, who in one “intervention” tells him:
Dear Ted: It’s “encyclopedia,” not “encyclopaedia.” You always pronounce things in the most pretentious way possible, and it makes you sound douchy, and not “douchay.”