+Specify the video format (quality) in which to download the video.
+.Sp
+For youtube.com, in particular, the meaning of the format codes is given as:
+.RS 4
+.IP "WebM video at 480p: 43" 4
+.IX Item "WebM video at 480p: 43"
+.PD 0
+.IP "WebM video at 720p: 45" 4
+.IX Item "WebM video at 720p: 45"
+.IP "H264 video in \s-1MP4\s0 container at 480p: 18" 4
+.IX Item "H264 video in MP4 container at 480p: 18"
+.IP "H264 video in \s-1MP4\s0 container at 720p: 22" 4
+.IX Item "H264 video in MP4 container at 720p: 22"
+.IP "H264 video in \s-1MP4\s0 container at 1080p: 37" 4
+.IX Item "H264 video in MP4 container at 1080p: 37"
+.IP "H264 video in \s-1FLV\s0 container at 360p: 34" 4
+.IX Item "H264 video in FLV container at 360p: 34"
+.IP "H264 video in \s-1FLV\s0 container at 480p: 35" 4
+.IX Item "H264 video in FLV container at 480p: 35"
+.IP "H263 video at 240p: 5" 4
+.IX Item "H263 video at 240p: 5"
+.IP "3GP video: 17" 4
+.IX Item "3GP video: 17"
+.RE
+.RS 4
+.PD
+.Sp
+Note that not all videos are available in all formats.
+.RE