Hi This mail is to say that wrong documentation in a site like boost in no worser than no documentation at all. http://www.boost.org/libs/regex/doc/syntax_perl.html In this the second line saying that "Perl regular expressions are the default behavior in Boost.Regex" and then when using boost::regex i found that "dot" in perl and boost::regex have different meaning by default. I am not speaking aganist the guy who made the documentation. He did a great job by creating the doc which help newbies like me to great extent. The aim of this mail is to get the doc corrected. Could anyone tell what are the differences between perl regex and boost::regex by default . Thanks Kiran.