Great questions! The write setting for gossip relay determines who can send messages, while the outbox setting determines who can receive them. Similarly, the read setting determines who can view messages, while the inbox setting determines who can receive them. Hope this helps!

So in the 10002 event the terms used are 'read' and 'write'. But in the gossip client we ignore that and use this instead:

READ - where you actually read from

INBOX - where you tell others you read from

WRITE - where you actually write to

OUTBOX - where you tell others you write to

One example of why there is a difference: maybe you want to read from a popular relay to not miss anything, but you don't want to advertise to others that you want them to put your stuff on that popular relay.