Registering in a band means that users who do not have an account on your server can register the protocol using the XMPP protocol, so registration remains “in the band” inside the same protocol that you already use. This is contrary to doing out of range registration, for example, by going to the registration site and then returning to the XMPP client software. XMPP defines an in-band registration method in XEP-0077 , and many XMPP clients support it.
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