[1] remote: は URL scheme です。

[2] <iframe> - HTML | MDN ( (2013-03-29 14:07:01 +09:00 版)) <https://developer.mozilla.org/en-US/docs/HTML/Element/iframe>

[3] Using the browser API - Web API Interfaces | MDN ( (2014-09-24 06:18:41 +09:00 版)) <https://developer.mozilla.org/en-US/docs/Web/API/Using_the_Browser_API>