F.L.S., Fellow of the Linnæan Society.
F.M., field-marshal.
fo., fol., folio.
F.P., fire-plug.
F.P.S., Fellow of the Philological Society.
Fr., France; French.
F.R.A.S., Fellow of the Royal Astronomical Society.
F.R.C.P., Fellow of the Royal College of Preceptors, or of Physicians.
F.R.C.P.E., Fellow of the Royal College of Physicians, Edinburgh.
F.R.C.S., Fellow of the Royal College of Surgeons.