title: Certificate subject X.509
body: <p>According to the X.509, a certificate has an attribute subject. </p>
  
  <pre>
  C=US, ST=Maryland, L=Pasadena, O=Brent Baccala, OU=FreeSoft,
  CN=www.freesoft.org/emailAddress=baccala@freesoft.org
  </pre>
  
  <p>This is the typical subject value. The question is what are the types(or tags) of those attributes(C, ST, L, O, OU, CN) and what is their format?</p>