Bearer Form
  
That's bear-er. No nudity involved.
Securities can be issued in two ways: registered, or bearer. Most are registered, meaning that the issuer (the business that sold the security) sends out the payments to the owner of their own accord. The business even keeps track of the security should the original owner sell it.
With a security in tbe bearer form though, there is no record of it, and whoever has the physical certificate in hand is assumed to be the owner. The obvious risk comes in the potentiality of you losing the certificate (yikes), but the upside is that it makes it easier to avoid transfer taxes.