if you own say 100,000 shares and you order the certificate, it just means that those have to be legitimate shares. the piece of paper looks like a diploma. it has the no. of shares and your name on it. Before you can sell those shares, you have to present the certificate to the broker. it prevents someone from selling you bogus shares like a short does. They actually have to have those shares to sell you. Thats why Grim keeps saying take possesion of your certificate. it works against the shorts.