After throwing his second interception of the night against the Bears, 49ers quarterback Colin Kaepernick was flagged for a 15-yard penalty for "inappropriate language." Kaepernick is the first player to be hit with a penalty of this sort, and while nobody's sharing exactly what Kaepernick said, it's fairly safe to assume he went beyond the realm of mere profanity.
In the wake of the Richie Incognito and Riley Cooper scandals, the NFL floated the idea of making use of the word "nigger" on the field worthy of a 15-yard penalty. That specific rule was never put in place, but the competition committee made policing the use of racial and homophobic slurs, which could already fall under the unsportsmanlike conduct penalty, a point of emphasis for officials. From SI:
During a conference call with the media Wednesday, committee chair Rich McKay and committee member Jeff Fisher emphasized that officials can flag players for obscene comments under the current rules.
"As we mentioned earlier, we have the current rule — unsportsmanlike conduct — Rule 12, Section
3," Fisher said. "It states that, 'Using abusive, threatening or insulting language, or gestures to opponents, teammates, officials or representatives of the league is unsportsmanlike conduct.'
"The N-word would fall under that category. The officials will be empowered to call a foul if there are racial slurs or statements regarding another player's sexual orientation, or even bating and insulting with verbal abuse. It falls under that. It is going to be a very significant point of emphasis."
Technically officials could use this new point of emphasis to penalize all bad language, but Fisher is making it pretty clear in that quote that racial and homophobic slurs is what they are really after. Referees aren't about to start throwing flags every time one player calls another a "motherfucker," because no game would ever get finished.
Kaepernick was asked after the game if he had used any kind of slur while talking shit to the Bears defense, and he denied saying anything at all. We'll likely never know exactly what Kaepernick said, it's in the league's best interest to keep the "inappropriate language" umbrella as large and undefined as possible, but you can bet that when you see this penalty called in the future, it's not because someone said something mean about another player's mom.