Thanks!

DTD

So this means something like defining your own language? E.g.

 <barber></barber>, <scissors></scissors> 

instead of

 <paragraph></paragraph>, <bold></bold> 

etc. ?

But, really, you can just use a list for ordered pairs.

You can even pass an entire time series with JSON. http://vimeo.com/35005701

I sometimes wish JSON didn't allow any types of scalar data other than strings.

"Numbers are not quoted. It would be insane to require quotes around numbers." —Douglas Crockford http://www.json.org/fatfree.html