should be sent immediately upon the occurrence of the fortunate event
that calls forth congratulatory wishes; they should be brief,
gracefully worded and contain no mention of other matter. The
occasions in life that call forth such missives are numerous:
birthdays, engagements, marriages, anniversaries, business successes,
etc., each, or all, should win some congratulatory notice. The formal
congratulation is in set terms, usually written in the third person,
and may be used between individuals but slightly acquainted; for
example:
Mr. and Mrs. Stuart congratulate Mr. and Mrs. Fielding upon
the successful conclusion of Mr. Harold Fielding's college
course and express the pleasure with which they listened to
the delivery of his eloquent oration on Commencement Day.