A lot of people from my generation will never forget one of Boston's ZIP codes. If you aren't in your late twenties to mid-thirties but know someone who is, try telling such a person, "Send it to ZOOM!" Chances are fairly good that they'll chant, "Box three five oh, Bos-ton Mass, ohhh, two oooone, three foooour..."
Zoom was a TV show that aired on PBS in the early 1970s. It featured a bunch of kids in striped shirts performing various fun and interesting activities; one of the things they did was to speak in a code language. I, of course, had to know how it was done, so I wrote away (or more likely my parents did on my behalf) for their pamphlet on Ubbi Dubbi. It turned out that speaking Ubbi Dubbi simply involved putting an "ub" before every vowel sound. Ubif yubou spuboke ubit rubealluby fubast, nubobuboduby whubo dubidubn't knubow Ububbubi Dububbubi cubould ubunduberstuband yubou.
Ubbi Dubbi beat the heck out of Pig Latin in terms of (in)comprehensibility. Everyone knew Pig Latin. Or some version of it, anyway; everyone seemed to have slightly different rules for what to do when a word began with a vowel. Ome-say eople-pay ut-pay an-ay "-ay"-ay after-ay uch-say ords-way, while others used "-yay" or "-hay" or "-way." But whichever of those you picked, pretty much everyone could understand you. Ubbi Dubbi was private, reserved only for those cognoscenti who watched Zoom (and perhaps any parents who were paying attention).
There's another code language that used to be fairly widely known, called Double Dutch. I gather that it involves replacing every consonant sound with a syllable starting and ending with that consonant—suso wuworordodzuz cucouldud gogetut popruretutty lolongung. I suspect the rules were a little more specific than that—I seem to recall once seeing a table showing exactly what syllables were to be used in the consonant replacement process—but I've found that nobody I ask about Double Dutch has the slightest idea what I'm talking about. (And no, this language has nothing to do with the newly revived competitive jumprope sport of the same name.)
In trying to find out about Double Dutch, however, I came across yet another similar sort of code language, this one called Doublespeak; Beth Ochsner tells me it was spoken at camp when she was a kid. It had something to do with expanding the first vowel sound in a word into multiple syllables: a vowel x is replaced with xthe-gx. Sothego wothegords cathegame outhegout southegounding sothegomething lithegike thithegis.
I'm sure there must be other such languages; by all means ubop-drubay ube-mubay uba-ubay ubote-nubay if you know any, particularly if you can tell me any more about Double Dutch or Doublespeak.
(By the way, it appears that WGBH-TV in Boston is in the process of creating a new version of Zoom. Should be fun. And yes, the mailing address remains the same. Send it to Zoom!)