id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
20	[:class:] in regex	anonymous		"StringRegExp says that [:space:] is recognized.

But this one works: 

StringRegExpReplace($s,""^(re:|fw:|fwd:)\s*"","""")

but these didn't:

StringRegExpReplace($s,""^(re:|fw:|fwd:)[:space:]*"","""")
StringRegExpReplace($s,""^(re:|fw:|fwd:)([:space:])*"","""")
"	Bug	closed		AutoIt	3.2.10.0		Rejected	regex, regexp,StringRegExpReplace