i find it amusing that in 18 months of development of the nostr protocol it still hasn't occurred to anyone that letting users set expiry timestamps on notes might be a good idea for many reasons, including helping relay caches stay within reasonable limits.
classified advertisments and orderbooks are two clear examples of information with a definite, and short lifespan.
BTW vexl isn't based on nostr, so your comment is off topic in this thread. That said:
It would be nice to have flags on notes that mark the status of the note. Like expired (user could set a flag with a condition of crossing a certain date or any other parameter, that would switch the asigned flag on). But also a flag that says "old version of the note, the updated one is -note id link-". It is hard to delete a note on nostr, but this way one could be able to correct mistakes in a new note and link it to the old note in obvious way. Preferably nostr clients would display it in some intelligent way (as a vesions of the same note).
