Mail letters, in the past

• Mail rte.
• P.O. address
• Mail abbr
• Address abbr
• Letters on country letters
• Country rte.
• TV oldie "Mayberry ___"
• Rustic address abbr., once
• TV's "Mayberry ___"

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
also R.F.D. ; 1882, American English, it stands for rural free delivery .