pep.Nÿco, https://twitter.com/xmpp/status/1202136726426263553 was this you?
pep.Most of these are actually wrong :/ (or "not exactly correct")
pep.Except "Query your message history"
pep.MAM doesn't allow to store files. Search is not a default feature of MAM, it can be added and I believe ejabberd has a proprietary extension for that. I guess the job of synchronizing between multiple apps is shared between Carbons and MAM to some extent, and the last one is a server policy