You’re asking whether I can link from a certain page to this memo. The answer is Yes.
Let me break down the referencing. We have two matters:
Referencing a page or tag from inside a memo. I think this is relatively trivial. Using tags and backlinks we can easily do this.
Referencing a memo from a page. I think this is the matter you were asking. A memo is a block that lives outside a page. it doesn’t have a direct parent (the parent can be some internal page). It can be referenced the same way we reference other blocks.