A recommendation of Phoebe. Such recommendations were important, because there was both great legitimate need for this kind of assistance, and many deceivers who wanted to leech of the generosity of Christians.
Servant is the same word translated deacon in other places.
Phoebe seems to be a female deacon in the church, either through formal recognition or through her general service. Christians, on their conversion, seemed to feel no need to change their names even if there was some pagan significance to their name. Apparently they were now back in Rome. Chosen in the Lord has the idea of Rufus having some eminence among the Christians of Rome, not really referring to his election in Jesus. The value of Paul s extensive greetings to the Roman church.