A GET to http://example.net/templates/1 would return a template construct [1]. Assuming vnd.joe.templatelanguage was a language that used double-brace delimiters, it might return something like this:
<template mode="escaped" type="application/vnd.joe.templatelanguage"> <h1> {{BlogTitle}} </h1> <h2> {{EntryTitle}} </h2> <p> {{EntryBody}} </p> </template>
This is where my approach diverges:
I'm proposing that a response to a GET looks like this:
HTTP/1.1 200 OK Content-Type: application/vnd.joe.templatelanguage
...vendor specific bits...