+-b::
+ If any file doesn't begin with a From line, assume it is a
+ single mail message instead of signalling error.
+
+-d<prec>::
+ Instead of the default 4 digits with leading zeros,
+ different precision can be specified for the generated
+ filenames.
+
+-f<nn>::
+ Skip the first <nn> numbers, for example if -f3 is specified,
+ start the numbering with 0004.
+