Information on the 'pref' resource.

It should have an ID of 128. Most of the fields have an corresponding item on the
dialog, except for the “Change T Only”, “Change C Only” and “Exten” fields.

For Change T Only and Change C Only a value of ‘0’ means the check box is
unchecked, ‘1’ the “is” radio button is selected, and ‘2’ the “is not” radio
button is selected.

For Exten, ‘0’ corresponds to “none”, ‘1’ to “add”, and ‘2’ to “remove”.

The preferences file can live either with the En Mass application, in a folder
called “Preferences” in the System Folder.  For those who don’t want this extra
file En Mass with also look in the application for this resource.