An entry is accepted only with a token: a genuine write capability whose area covers it, and the holder's signature over the entry; three checks.

It is what makes a store trustworthy without trusting the peer that sent it.

An entry by itself is just a claim. Anyone could write a card with your room's name on it.

So every entry travels with a token stapled to it. A write ticket whose area covers the entry.

And a signature over the entry, by the ticket's holder.

A peer checks three things. Is the ticket genuine? Does it cover this entry? Did its holder sign it?

A store holds only entries that pass. Willow calls them authorised entries.

Check yourself. What three checks does a peer make before storing an entry?