<http://schema.org/keywords>
"full-screen"^^<http://www.w3.org/2001/XMLSchema#string>
<https://techcrunch.com/2013/01/10/google-hangouts-on-air-now-have-a-full-screen-option-for-your-broadcast/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A%20Techcrunch%20%28TechCrunch%29>