We've encountered reminders at almost every turn in recent years. The NFL rulebook is stuffed full of complex instructions, random exceptions and obscure scenarios. Simplifying the document, a hot topic of late, has been a matter of public discussion for some time.

In the absence of movement there, however, the NFL has gone on the offensive this year to explain its rules to the general populace. The effort has gone far beyond its longstanding practice of putting its vice president of officiating on the NFL Network to explain controversial calls and it has reflected a deeply-held league view that much of the criticism directed at officials is generated by confusion and misinterpretation rather than competence.

Current vice president of officiating Dean Blandino has begun appearing on some of the game-day videos the NFL produces to explain replay decisions. He also has called in to national broadcasts to provide background on decisions during games and tweets about particularly confusing or highly controversial plays.

The league, in addition, is producing a digital "Video Rulebook" on its operations website that explains what certain penalties look like. Fans can test their knowledge through a separate "You Make the Call" video series.

It shouldn't take that much work to educate fans on rules of a game, but it might be a more efficient approach than awaiting the uncertain results of any initiative to pare down the rules themselves. In the past two weeks alone, in fact, we've received multiple reminders about the obscure corners of the rulebook. Let's take a look at three of them.

Illegal substitution Sunday in Philadelphia

Situation: Fourth down from the Washington Redskins' 10-yard line, 12:10 remaining in the second quarter.

Play: Redskins' Tress Way punts 48 yards to Eagles' Kenjon Barner.

Penalty: Illegal substitution on the Eagles.

Analysis: When you watch the play, you see Barner field the punt near the Eagles' sideline with fellow returner Darren Sproles positioned close to the far sideline. After the teams returned from a timeout, referee Walt Coleman announced the penalty on Barner because he "came in at the last minute and did not get inside the numbers."

Coleman's explanation added to the confusion. Astute rulebook technicians know that an offensive player must advance beyond the painted numbers on the field to be considered a legal substitute, but defensive players -- and Barner was one because he was on the punt return team -- do not.

The rule itself is designed to prevent offenses from faking substitutions in order to confuse defenses attempting to match up. It doesn't want to penalize defensive players who run on the field but are ultimately called back.

The Eagles' return appeared designed to capitalize on that loophole, leaving the Redskins' coverage unit unaware that Barner would be in place to field the kick. But it appeared the Eagles got too cute.

It's not visible on the television broadcast, but based on Blandino's in-game tweet, Barner ran onto the field after the Redskins snapped the ball. That's prohibited by NFL Rule 5, Section 2, Article 4.

Coleman got the call right, if for the wrong reason. In the end, we learned that the painted numbers are important for offensive substitutions but not for the defense. File it away.

Coin toss at MetLife Stadium

Situation: Overtime coin toss between captains.

Play: New England Patriots captain Matthew Slater called heads, won the toss and asked to "kick off, that way."

Penalty: None, but referee Clete Blakeman granted the "kick off" part but not the "that way" part.

Analysis: Most of the attention on this play focused on whether coach Bill Belichick made the right decision to kick off in what turned out to be sudden death overtime (probably not, based on the numbers) or whether Slater erred in his request (complicated). But it also illuminated how precise an operation the coin toss, with its inherent options, really is.

As illuminated by Rule 4, Section 2, Article 3, the winner of the coin toss is allowed three options at the start of a game. He can defer, allowing the loser to pick first. He can choose whether to kick off or receive the kick. Or he can choose which goal to defend. The latter two options are available in overtime.

The captain can only choose from one of the option buckets, which is where Sunday's confusion started. The rulebook requires the referee to grant the captain's "first choice" and make clear that the decision is "final and not subject to change."

So if a captain's priority is to defend a certain goal -- to ensure it has the wind, for example -- then he must explicitly state it. The rulebook considers that a separate option from kicking off. If he says he wants to kick off, he is in essence giving his opponent the option to choose the wind.

Who knew a coin toss required such precision?

Illegal grounding on an interception in Week 15

Situation: Second down from the 50-yard line with 8:42 remaining in the first quarter between the Dallas Cowboys and New York Jets.

Play: Cowboys quarterback Matt Cassel threw an interception to Jets cornerback Darrelle Revis.

Penalty: Cassel was called for intentional grounding on the play, which the Jets declined.

Analysis: We naturally think of intentional grounding as a play when the quarterback wildly throws the ball to a big patch of green turf (from inside the pocket, of course) to avoid a sack.

In this case, however, Cassel didn't get enough on the throw and Revis intercepted it near the sideline. There were no Cowboys receivers in the area, and Cassel was still in the pocket, so referee Craig Wrolstad had no choice but to throw the penalty flag.

Here's another twist: Quarterbacks can also be called for intentional grounding on a completion to an ineligible receiver. That happened Sunday to Cleveland Browns quarterback Johnny Manziel, who flipped a pass to offensive lineman Mitchell Schwartz while under duress in the fourth quarter of a 17-13 loss.

Referee Walt Anderson could be heard on his microphone saying, "All right, hold on" before convening a conference of his crew. Ultimately, Anderson penalized the Browns for illegal touching (Schwartz was an ineligible receiver) and intentional grounding, because the ball never got past the line of scrimmage in the direction of an eligible receiver.