Niles is, like Ringo insists he himself is in "A Hard Day's Night", not a mod or a rocker, but instead a mocker. Cal, on the other hand, is consistently pretty damn mod and that's really it. Technically, because the Schnitzels are from the 23rd century and therefore part of the post-post-post mod revival, this is a trivial issue. Fun fact, according to one of my many books, in reality, it was John Lennon who said the "mocker" line to the press, and Ringo who penned John's "turn left at Greenland" comment. They pulled a switcheroo in that press conference scene in the movie. Why? To be sardonic, probably; the Beatles were the original trolls, y'know. Kings of "screw you" humor. I love that.