=back
-Note that not all videos are available in all formats.
+Note that not all videos are available in all formats and that other
+sites supported by B<youtube-dl> may have different conventions for
+their video formats.
=item --all-formats
Do not use the I<Last-modified> header to set the file modification time.
+=item --extract-audio
+
+Create an audio-only file extracted from the video downloaded. Requires that
+ffmpeg and ffprobe be installed.
+
+=item --audio-format=B<FORMAT>
+
+Set the audio format to be used for the extraction. Possible values are
+I<best>, I<aac>, I<mp3>, with I<best> being the default.
+
=back
=head1 OUTPUT TEMPLATE