Oxford UP was kind enough to send me a copy of Slang: The People’s Poetry, by Michael Adams, and if you’re interested in the subject, you’ll want to read it. The author is an actual lexicographer and historian of English, but he’s comfortable with popular culture—he’s also the author of Slayer Slang: A Buffy the Vampire Slayer Lexicon. But most importantly, he thinks clearly and writes vividly. Here he is on the distinction between slang and jargon:
But the social circumstances that provoke jargon are different from those that provoke slang: in jargon, there’s something at stake beyond positioning oneself in the social circumstance. Jargon may be stylish, but it is not, as Eble suggests of slang, analogous to fashion: jargon has to roll up its sleeves and do real work. There is nothing playful about on a wait, triple-sat, or four-top; these are all shorthand for things that folks working in restaurants don’t have time to say at length. For instance, when a server returns from a break, another says, in passing, “We’re on a wait,” not “We have more patrons than we can serve at one time.” The second server is passing because she has just been triple-sat and she doesn’t have time to explain, or she’ll be weeded. Note that “I’m weeded” takes less time to say than “I am in the weeds.”
In slang, clipping’s cazh [casual], but in jargon it’s efficient. When a server behind you quietly says Backs, there’s nothing casual in the message: it’s a warning that said server is carrying a full tray and that no one within distance of a stage whisper should move. … In this situation, if you don’t understand restaurant jargon, if you don’t respond to it as a member of the guild, the results will be catastrophic. …
So jargon is practical: it’s brisk and unambiguous, and it helps busy people do their jobs efficiently. But its use is also social: social relations within the restaurant depend on it, and efficient work for the common goal depends on cerain social relations. When restaurant jargon is slangy—full of fun, invention, and irreverence—it reinforces the restaurant in-group’s camaraderie and alleviates the tedium of its shared labor.
Later he makes the point that jargon tends to be homogeneous: “servers in California use terms familiar in Indiana, Ohio, New York, and New Jersey.” And he discusses edge cases: “At Winchester, one of England’s great public schools, students have spoken a peculiar slang over so many centuries that it looks surprisingly like jargon. An item of Winchester slang is called a Notion, a term that is itself a Notion.”
After the initial section on definitions, he has chapters on the social, aesthetic, and cognitive aspects of slang, ending with a section titled “Toward a Poetics of Slang,” which begins, charmingly, “It should be clear by now that I’m more inclined to complicate matters than to get to the bottom of things” and ends by saying slang “cannot be understood without considering its relation to every relevant aspect of language, the slight but irreducible area of a spandrel amid the lines and arcs and space of the grand design of language…” And each chapter ends with a full bibliography. A fine job.