關於個Re字in formal letter

[re] is the short form for [with reference to]. In a fromal letter, one can start the letter with [With reference to xxxxxxx], or if a subject line is used, put in [Reference: xxxxxxxx]. Sometimes one would specify [Your Reference: xxxxx] or [Our Reference: xxxxxx].

2009-10-27 07:18:03 補充：
Oops, [formal] was mis-spelled as [fromal].

re /riː/


preposition
FORMAL
(especially in business letters)
about; on the subject of:
Re your
communication of 15 February ...

寫re唔係formal letter，多數係email或memo，re係regarding嘅短寫，意思係關於或有關。