mod_pubsub_serverinfo: Treat public providers as public The opt-in mechanism is to prevent leaking domain names or relationships between small private servers. These are not considerations relevant to public servers. We use the providers.xmpp.net API to fetch a list of known public provider domains.

This module blocks configured queries that change server state.

E.g. to make vCard storage read-only:

``` lua
readonly_stores = {
	vcard = { "vcard-temp", "vCard" };
}
```