Check your json script, under the heading Syntax.
$json.enc(<URL>)
Encodes a URL. Uses JavaScript's encodeURI().
Yes, I see it there but with my knowledge poll it's quite limited what that tells me. Or what it does/how to use it properly
Edit: Of cause I understand it now that Loki explained it etc, but thanks for pointing it out that it was there all along :P.
