<http://schema.org/keywords>
"nfl player safety nfl troy vincent Marcus Mariota Ryan Tannehill nfl competition committee nfl rule changes nfl protecting quarterbacks nfl quarterback rules"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.si.com/nfl/2016/03/14/player-safety-competition-committee-quarterback-protection-low-hits>