This is a list of commonly and uncommonly used abbreviations that are used in the subject box of an English-language email header.
These words are inserted in the middle of or at the end of the subject, usually by the author.
This is a list of abbreviations which are less commonly used in the subject of an English email header: The email client will typically check for an existing "Re:" when deciding whether or not to add one in front of the subject.
Whereas "Re:" stands for "re" in Latin (see Standard prefixes), it is often taken to mean "regarding", "reply" or "response" in English, and in most other languages, similarly, the abbreviation corresponds to the word for "response" or "reply."
To avoid the issue of convoluted subject lines mentioned earlier, email clients may have an option to force the use of the standard (RE) and English (FW) abbreviations even when all other features are presented in another language,[3] or to recognize other forms.