R2D2 (and several similar Astromech droids) are generally not equipped with a vocabulator, and instead communicate using a well-established series of electronic beeps, "bloops," buzzes, chirps, whines, and whistles known as Binary.
Obviously, Binary is a homonym of the generally recognized term "binary" and is very different in that it is a fully expressive language rather than a numeric representation system. As such, simple 1's and 0's are insufficient to represent Binary.
I've scoured the canon in search of Binary, however most books and comics use the onomatopoeic representations of "beep", "blop", "blip", et cetera, relying on other characters for interpretation. Clearly, simple English words are insufficient to express tonality, duration, and other aspects (especially emotional) of Binary. It seems to me that one could develop a compact representation of Binary, not dissimilar to Morse code.
If there's not a canonical textual representation of Binary, what would be an efficient human-readable representation of Binary?