R., L. recipe, take.
R.A., Royal Academy, or Academician; Royal Artillery; Rear-Admiral; Right Ascension.
R.C., Roman Catholic.
Ref. Ch., Reformed Church.
Reg. Prof., Regius Professor.
R.I.P. (L.), requiescat in pace.
R.Rev., right reverend.
R.S.A., Royal Society of Antiquaries; Royal Scottish Academy.
R.S.S. (L. regiæ societatis socius), Fellow of the Royal Society.
Rt., Right.