 <p>As said, you're asking about regular expressions commonly called a "regex". Take a look at <a href="http://www.regular-expressions.info/reference.html" rel="nofollow"><strong>Regular-Expressions.info</strong></a> for tons of good information. The page you're probably most interested in is the <a href="http://www.regular-expressions.info/characters.html" rel="nofollow"><strong>Literal Characters and Special Characters</strong></a>, which largely answers your OP. A great site to test your regex is <a href="http://www.rubular.com/" rel="nofollow"><strong>Rubular.com</strong></a>. It's designed for Ruby, but works great for nearly anything I've thrown at it (sed expressions, C# replace, JS replace, etc.).</p> <p>HTH</p>