The df (day first) and mf (month first) parameters indicate the intended date format to display. The appropriate parameter should be set to "y" or "yes" e.g. df=yes or mf=y.
The default output of this template is to display the month before the day (American format). This default may not be appropriate articles about people from parts of the world where the day precedes the month in a date (British/International format). In such articles the parameter, "df", should be set to display the day before the month.
The parameter "mf", while not actually used by the template, will indicate that month first format is intended. Using these parameters can assist bots or other automated processing to detect which date format is intended; leaving the format as default may lead an editor or bot to change the format to an unintended value.
Do not specify both "df" and "mf" parameters in the same use of the template, as these formats are mutually exclusive.