tt>Is</tt>: Both <tt>\p{L}</tt> and <tt>\p{IsL}</tt>

 denote the category of Unicode letters.  Blocks and categories can be used
 both inside and outside of a character class.

 <p> The supported categories are those of
 <a href="http://www.unicode.org/unicode/standard/standard.html">
 <i>The Unicode Standard</i></a> in the version specified by the
 <A HREF="../../../java/lang/Character.html" title="class in java.lang"><CODE>Character</CODE></A> class. The category names are those
 defined in the Standard,