[gbpin]

It's supposed to mean that the API responds with JSON data (as opposed to, say, XML). "REST" here just means we use standard URL patterns and rely on HTTP verbs (e.g. GET), to get stuff done.

[ishi]

I think you're missing a "currency" field in the request, particularly since you support both AUD and USD.

[dekz]

Sorry I was probably being overly pedantic, I do understand the concepts of REST and the JSON format. I've never seen it as one buzz phrase though.

[steelaz]

I wouldn't call it buzz phrase, I see JSON REST API and I know exactly what it is and what to expect from it.