Yes, that's exactly what I mean. It's like saying "we use JSON as our file format", but worse. > "So this program saves its data as 'S-expressions'." > "Oh, co

Yes, that's exactly what I mean. It's like saying "we use JSON as our file format", but worse. > "So this program saves its data as 'S-expressions'." > "Oh, cool. Which dialect?" > "Uh, I don't know. It doesn't say in the README. It just says 'S-expressions'." The answer can be CL, Scheme (lots of variations and dialects even here), the never-finished SPKI Sexps, OCaml sexps, something that the new dev on the team cooked up last Tuesday that vaguely resembles what they learned as "lisp" in college, or something else entirely. On the other hand, if one were to say "this program uses R4RS S-expressions" (or, presumably, "CL S-expressions", but I haven't read the relevant bits of CLtL), you'd immediately be in a much nicer place than JSON can offer. Not only would you have a well-specified syntax for a reasonably broad range of data types, you'd have a useful equational theory as well. [ETA: Unless you want unicode. Doh. R6RS, maybe.] Ah, the impossible dream.