title: The use of the underscore in host names
body: <p>Wikipedia states that underscores <a href="http://en.wikipedia.org/wiki/Hostname#Restrictions_on_valid_host_names" rel="noreferrer">are used by both Android and Microsoft Windows Systems in hostnames</a>.  My question is,  what are these host names?  Do you have examples of these strange hostnames names and what they are used for?</p>