-Note that these variables are only used to initialize the default
-value of `calendar-holidays'. In other words, they only have an
-effect on the displayed holidays if set before the calendar is
-loaded. After the calendar has been loaded, you must customize
-`calendar-holidays' directly.
+The aforementioned variables control the holiday choices offered
+by the function `list-holidays' when it is called interactively.
+
+They are also used to initialize the default value of
+`calendar-holidays', which is the default list of holidays used
+by the function `list-holidays' in the non-interactive case.
+Note that these variables have no effect on `calendar-holidays'
+after it has been set (e.g. after the calendar is loaded). In
+that case, customize `calendar-holidays' directly.