===Literal (Simple) Regular Expressions===
xThe simplest regular expression is a series of letters and numbers, possibly including white space (tabs or space characters), that have no special meaning. Such a regular expression consists of ``literals''; that is, normal letters, which match only an identical letter in the data being searched.<br><br>For example:�This is a regular expression�When an editor searches for a literal regular expression, it can only score a ``hit'' if it finds exactly that sequence of characters in the data it is searching. <br><br>Reference: http://osr507doc.xinuos.com/en/OSUserG/_Literal_chars_in_regexps.html
===Complex Regular Expressions===
