For an example, you can go to my page on Occam’s Razor and scroll to the bottom to see all the backlinks to that page (i.e. all the places where I link to Occam’s Razor).
This prototypes a possible way to link between different people’s knowledge graphs using the familiar structure of URLs. This relates to the idea of a World Knowledge Graph, and I discuss it more in my post on How Logseq should build a World Knowledge Graph.