Redirect a directory
<rule>
<from>/some/olddir/(.*)</from>
<to type="redirect">/very/newdir/$1</to>
</rule>
Clean a url
<rule>
<from>/products/([0-9]+)</from>
<to>/products/index.jsp?product_id=$1</to>
</rule>
eg, /products/1234 will be passed on to /products/index.jsp?product_id=1234 without the user noticing.
Browser detection
<rule>
<condition name="user-agent">Mozilla/[1-4]</condition>
<from>/some/page.html</from>
<to>/some/page-for-old-browsers.html</to>
</rule>
eg, will pass the request for /some/page.html on to /some/page-for-old-browsers.html only for older browsers whose user agent srtings match Mozilla/1, Mozilla/2, Mozilla/3 or Mozilla/4.