ChangeLog prologues are small pieces of informative text that Patcher adds above each ChangeLog insertion in the mail buffer.
When the ChangeLogs appearance is verbatim, Patcher inserts one
prologue per ChangeLog file. The prologue's contents is controlled by
the :change-logs-prologue project option (a string). A ‘%f’
appearing in this string will be replaced with the ChangeLog filename.
The default value for patcher-default-change-logs-prologue is
"%f addition:".
When the ChangeLogs appearance is pack, Patcher inserts only one
prologue for the whole ChangeLogs patch. When patch, there is a
single prologue for both the ChangeLogs and the sources. For customizing
the prologue in both of these cases, see Diff Prologue.