Chapter 3 Authentication for FortiOS 5.0 : Certificate-based authentication : Certificates overview : Certificate types on the FortiGate unit : Local certificates
  
Local certificates
Local certificates are issued for a specific server, or web site. Generally they are very specific, and often for an internal enterprise network. For example a personal web site for John Smith at www.example.com (such as http://www.example.com/home/jsmith) would have its own local certificate.
These can optionally be just the certificate file, or also include a private key file and PEM passphrase for added security.
For information about generating a certificate request, see “Generating a certificate signing request”. For information about installing a local certificate, see “Obtaining and installing a signed server certificate from an external CA”.