PMDF has several pop-up forms which can be invoked at the To:, Cc:, or Bcc: addressing prompts from within PMDF MAIL, VMS MAIL, or DECwindows MAIL. The forms include

• the CCSO addressing form used to obtain e-mail addresses by querying a CCSO directory; (note that CCSO directories are sometimes referred to as ph, qi, or gopher directories);
• the FAX addressing form used to construct one or more PMDF-FAX addresses; and
• the LDAP/X.500 addressing form used to obtain e-mail addresses by querying an LDAP directory or X.500 directory via an LDAP server.

Note that from DECwindows MAIL, the forms do not appear until after the SEND button is pressed in the "mail create" window.