I've seen subject lines like
Re: AW: [xsl] Syntax Problem
What does the AW mean?
Antwort ("Answer" in German).
Now a more difficult question: what does "RE" mean?
http://www.webfoot.com/advice/email.re.html
From the Beginner's Guide to Effective Email:
"Re" is a Latin word meaning "about", as in the title of the important
medieval book De re metallica.
"Re" has probably been used in correspondence since before there was
correspondence in English.
Now, most people think of "RE" as an abbreviation for "REgarding".
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list