D._ So also letters following a name indicating membership of certain scientific and artistic organizations.
_F.

R.G.S._ (Fellow of the Royal Geographic Society).
_R.

A._ (Member of the Royal Academy).
So also in the United States and Great Britain, _M.

C._ (Member of Congress) and _M.

P._ (Member of Parliament).
Where a person has many titles the following of this rule involves certain difficulties.