Note 48 — 40. Letter Writing
Reading edition
Note 48 (page 96). It seems inadvisable, in the present state of conflicting usage, to follow the greeting of some letters with a comma and of others with a colon. Not only may this arbitrary distinction prove embarrassing when a writer does not wish definitely to commit himself as to whether his letter is strictly business or merely friendly, but it also compels the teaching of two forms where one will do.