set only-type-headers

SET ONLY-TYPE-HEADERS [fields]  -  define header fields to be shown

The ONLY-TYPE-HEADERS variable defines one or more header fields as the
  only ones that should appear when you display messages with TYPE, 
  READ, REVIEW or BROWSE.

The command LITERAL TYPE ignores this variable.

To unset it, type SET ONLY-TYPE-HEADERS with nothing following.

ONLY-TYPE-HEADERS overrides the variable DONT-TYPE-HEADERS.

Example:
    MM>set only-type-headers date, from, subject
  You might do this before displaying a set of messages, to reduce the 
  space taken up by the headers.  

For more help, type "help" and one of the following:
(at any prompt:)  save-init   set   show   type   set dont-type-headers
                  set only-print-headers   set dont-print-headers
(at the MM> prompt:)  read   review   browse