look too intuitive to me. R? L? X? But maybe the learning
curve is short.
well, if i were designing my own format, perhaps i wouldn't use single letter
keys to embed metadata. still, after you've used it even a little bit, it
becomes fairly easy to remember. (and for reading, most of the fields are
obvious: R is 'rhythm', K is 'key', etc.)
Remember that it will be used by people from many languages. The
abbreviation one language may not make sense on another. They may even
not be using letters for naming the notes!