mh-invisible-header-fields-default

mh-invisible-header-fields-default is a variable defined in `mh-e.el'.
Its value is

nil

Documentation:
*List of hidden header fields.

The header fields listed in this option are hidden, although you
can check off any field that you would like to see.

Header fields that you would like to hide that aren't listed can
be added to the option `mh-invisible-header-fields'.

See also `mh-clean-message-header-flag'.

If you think a header field should be added to this list, please
update SF #1916032 (see URL
`https://sourceforge.net/tracker/index.php?func=detail&aid=1916032&group_id=13357&atid=113357').

You can customize this variable.

This variable was introduced, or its default value was changed, in version 8.0 of the MH-E package that is part of Emacs 22.1.