A period follows abbreviations such as P.Eng., P.Geol., Ph.D., B.A., M.Sc., Ms., Mr., Dr., Jr., Sr., St. (Saint), a.m., and p.m.
Put a single space between the initials of a person’s given names:
E. B. White
Do not put any space between initials in abbreviations:
AER, P.Eng, N.W.T.