phranque - 6:51 am on Nov 25, 2007 (gmt 0)

the 2 curly braces means 2 of the previously specified pattern, so (([a-z][-a-z0-9]{2})[-a-z0-9]*[a-z0-9]) means an alphabetic character, followed by two dashes-or-alphanumerics, followed by zero or more dashes-or-alphanumerics, followed by an alphanumeric.