Must be refs to notes that Primal's caches have either not seen or dropped.

Unlike Snort, in Primal you get your notes from their cache server - so, it also decides what it should not show. Chances are those posts became part of it. And, I don't know which relays it caches from.

Try to see if you can see the same note in Snort.

1. Change the `nevent1` part to `note1`

2. Append to: snort.social/e/ - i.e.: snort.social/e/note1....

3. Paste in a URL bar and see if it loads or not.

The nostr: prefix has a few use-cases in clients:

- Mentions. The most universal way is to start with nostr: and then follow with an npub. This is a very direct mention. When you type an @, most clients will show you an autocomplete list as a mini-search. But when you pick someone, it often turns into the nostr:npub... notation

- Quoting events. As you already saw, when you append a note identifier - nostr:note1... - then you can quote other posts.

- Pointing at certain events. Not all clients understand all things that happen in Nostr. But you can still point at it with the nostr:nevent1... notation. Though, I see this quite rarely being used. But it's worth mentioning.

Usually, "note1..." refers to a text post, "nevent1..." to a non-post but Nostr event and "npub1..." as well as "nprofile1..." are identical... i think.

Hope this clears things up!