 <HR>
      <p></p>
      <P>Captures are the iterator ranges that are "captured" by marked sub-expressions 
         as a regular expression gets matched.&nbsp; Each marked sub-expression can 
         result in more than one capture, if it is matched more than once.&nbsp; This 
         document explains how captures and marked sub-expressions in Boost.Regex are 
         represented and accessed.</P>
      <H2>Marked sub-expressions</H2>
      <P>Every time a Perl regular expression contains a parenthesi