Systems which display backlinks to a node permit a new behavior: you can define a new node extensionally (rather than intensionally) by simply linking to it from many other nodes—even before it has any content.
I first noticed this in Conor White-Sullivan’s behavior with Roam. He wrote about our conversations in several notes throughout his system (ephemeral daily logs, feature lists, etc). As he was doing that, he wrote certain noun phrases (e.g. my name) as links. Those nodes had no content of their own, but as he did this across several days, they began to develop an implicit definition within his system, expressed through the backlinks.
This effect requires Contextual backlinks: a simple list of backlinks won’t implicitly define a node very effectively. You need to be able to see the context around the backlink to understand what’s being implied.
I find this particularly useful for terms of art and proper nouns of all sorts.
I’m also experimenting with this technique in my cooking notes; see e.g. Cabbage (but the backlinks will not unfortunately be visible on my public notes, since they’re from my private weekly journals).