Mechanism to embed *any* accessible Internet source in a webpage?

<i>Possible silly question from not a very technical person alert</i>. This just suddenly came to my mind. Not very sure if it makes sense or not. But it generally originated from the fact that the ability to refer to sources that support arguments, statements or any other forms of information is very important in order to verify those claims. And that platforms such as twitter and youtube enable you to embed their sources in a way they dictate you, but that there exist no general mechanism to embed information from sources that don't expose such embed codes for the general public.<p>So my question is: Is there a general purpose protocol/mechanism/tool for embedding any possible Internet source within your web-page in a standardized manner?<p>I mean in the way that you, as an Internet-publisher/writer/blogger/social net-worker: - visit a website that supports this mechanism/protocol - identify words/lines/paragraphs/multimedia or other HTML-chunks that you want to use as a reference for your own article. - you make a selection of that and invoke some task that enables you to copy an embed code that refers to this particular selection - you paste this embed code within your blog-post/website/status update/etc<p>And in the way that others, as visitors: - Read your text - See these embedded references, be they in the form of text or multimedia, that refer to the original source and are clearly identifiable as such - Are able to identify particularities of the original source from within the external page (URL, author if applicable, date) - Are able to click on it in order to navigate to the particular page and instantly jump to the right position by an anchor which preferable also highlights the particular source of reference