[1] remote: は URL scheme です。

[2] <iframe> - HTML | MDN ( (3/29/2013, 5:07:01 AM 版)) <https://developer.mozilla.org/en-US/docs/HTML/Element/iframe>

[3] Using the browser API - Web API Interfaces | MDN ( (9/23/2014, 9:18:41 PM 版)) <https://developer.mozilla.org/en-US/docs/Web/API/Using_the_Browser_API>