repeat for even more details
By default the program prints only titles of the found book. With one
-option `-d` it also prints the list of authors and genres.
+option `-d` it also prints the list of authors and genres, and also
+series the book belongs to (if any) and the serial number of the book in
+the series. With two options `-d` (`-d -d` or simply `-dd`) it also
+prints the file date, language and file extension.
Extension search
^^^^^^^^^^^^^^^^