I haven't found two titles that match. ISBN tag maybe needs to follow the spec in NIP 73 for 30040.
I'll check out NIP-73 👀
What do you mean about matching titles? If you give some more context I can investigate.
I was looking for two events one 30040 and one 30041 with the same title.
30040 and 30041 events aren't expected to have matching titles. 30040 events act as an index of multiple 30041 events, so the name of the index/collection will likely differ from the names of the individual 30041 fragments of which it is composed.
are the "e" tag events in 30040 events 30041? they will have to match somehow I think.
Yes the e tags in 30040 events reference 30041. The reference format is kind+pubkey+d-tag, IIRC. So the e tag references should include a d tag that shows up in some 30041 event.
e tags in 30040 can reference any event kind, includind 01 or other 30040. We just defined 30041 as the default kind.
Ope I hadn't thought about that yet! We'll need to add some extra rules for rendering non-30041 events in our viewer.