<http://schema.org/description>
"SlickLogin, a startup that lets users use a sound emitted by their smartphone either as a replacement for a password or as an additional 2-factor security layer, has placed a notice ..."^^<http://www.w3.org/2001/XMLSchema#string>
<http://thenextweb.com/google/2014/02/16/sounds-passwords-startup-slicklogin-says-acquired-google/>