https://lists.w3.org/Archives/Public/public-html-bugzilla/2011Aug/2532.html
[Bug 13592] Intentional that video/video (i.e. without src or source) is valid but...
https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=ISS013&roll=E&frame=13592
Astronaut Photo ISS013-E-13592 MYANMAR (BURMA)
astronautphotoemyanmarburma