The idea of a backlink is as old as the concept of a hyperlink, but they’re not as widely implemented as one-way links. A backlink is just a link that goes both ways – if you link to a page, that page knows that you’ve linked to it and can link back to you. In a way, hashtags are one of the most common forms of backlink – posts with hashtags are linked to a page that show you all the things linked to it. Following a hashtag means ending up at related content. Backlinks are like that, but just without the page in the middle. You link to a page, and the page knows you linked to it. This is really easy to do with Octothorpes.
This page has been octothorped with these terms
BACKLINKS
Add a special attribute to outgoing links on your page
If the page you linked to endorses incoming links, they’ll be notified and get data they can use to automatically link back to you.
If your page is being indexed by an octothorpe server, all you have to do is add the rel="octo:octothorpes" attribute to any link will turn it into a backlink an Octothorpe server can parse.
The following link will register a backlink originating from the page it’s on with all your connected servers.
<a href="somecoolurl.com/cats" rel="octo:octothorpe">Read about cats</a>
Note that you can still use all the normal rel attributes.
Of course, if you don’t control somecoolurl.com whoever does might not want to be part of some sort of backlink nonsense. Unless they confirm the link, they won’t! It just stays a link, and you’ve just told your servers that your URL links to that other URL.
But if the owners of somecoolurl.com want to create a relationship between your pages, they can. Lets say your site is called originating-site.com
<link rev="octo:octothorpes" href="https://originating-site.com">
That tells the Octothorpe server that you endorse links originating from the specified URL, and they’ll be registered as backlinks. You can then ask the Octothorpes server for backlinks to any page on your site, and display them however you want. If you’re really open to backlinks you can endorse all incoming links from your connected servers with a wildcard:
<link rev="octo:octothorpes" href="*">
Here is an example of a page that is backlinked from this page, but does not endorse the incoming link: No Backlinks or Page with Spaces in URL
revis an obsolete part of HTML spec originally proposed to denote a reverse link. We think it’s a good idea, so we’re bringing it back.Also note that, right now, endorsing backlinks is done at the domain-level, but finer-grained moderation controls are planned.