[daveloyall]

I think the author is more concerned about the source of the links rather than the style.

A file separate from the content could contain links and each one could be anchored to the top, bottom, or a particular phrase using ordinary regular expressions.

    /ordinary regular expressions/href=https://en.wikipedia.org/wiki/Regular_expression
    /$/text="This link is at the bottom";href=http://news.ycombinator.com

An observation: promoting 3rd party links to first-class status need not deny the author the ability to create hotspot links. I, for one, would configure my memex to always show the author's own links (of any style, as an overlay) and also any links that my friends and family might have created.

I'm not sure how my memex could locate links made by people I don't know. But, I imagine that the federated wiki people or the DHT people or the BTC people might have some ideas.

[dunham]

If the document were html, something like epubcfi might work better than regular expressions. This is what the epub people are recommending for a similar use case - sharing highlights and notes in epub books whose content may be updated.

For locating links/comments from people you don't know, I'd imagine a service like Google. Something that indexes the entire web and answers queries about which links overlay this document. I'd think they'd have to be ranked somehow. (Technically, Google already does this with "link:http://..." queries, but standard HTML links don't reference document fragments.)

[daveloyall]

Never heard of epubcfi but yes, if they came up with a way to highlight specific portions of a text, then yep, that would do it.

Regarding using google as a lookup service for something as fundamental as this.. No. It's important for the health of the Internet that we not do that. See https://tools.ietf.org/html/draft-nottingham-stakeholder-rig... . :)