Just a week into the 2016 playoffs, we've seen some quirky rules applied. Here are five more actual NHL rules that many fans may not have heard of.

The Hockey News

Well, if nothing else, the first round of the playoffs has been educational.

On Saturday, fans learned that a player can be offside even if his skate is clearly still over the blueline, because it has to be touching. That was news to some of us, and leads to some interesting philosophical questions. If a player jumps across the line with both skates in the air, is he onside? Offside? Both at the same time, like Schrödinger's cat?

Then on Sunday, we found out that you can get an interference call for touching the puck from the penalty box. That one has come up before, but it's rare enough that many fans were probably hearing about it for the first time. So that's two new rules that at least some of us weren't aware of in a single weekend – and that's without even getting into whatever it was that happened on that Antoine Roussel goal.

Well, why stop there? Every now and then, it's fun to dig into the NHL's official rulebook and find some of the oddities, quirks and loopholes hidden within. Many are rarely enforced, or have literally never come up in a real game. But they're still in the books, and fans might as well get to know them. As we've been reminded this week, you never know when an obscure rule will turn out to be crucial.

Here are five actual NHL rules that many fans may not have heard of.

The other area where a goalie can't play the puck

Every fan knows about the trapezoid behind the net, and the sections of ice on either side of it in which a goalie is forbidden to play the puck. (Well, almost forbidden – there's a little-known exception for goalies who keep one foot in the crease.) But many fans forget that there's another section of the ice where a goaltender isn't allowed to touch the puck. And it's much larger.

According to rule 27.7, a goalkeeper can't touch the puck or otherwise participate in the play on the other team's side of center ice. That's a minor penalty. And while it's a situation that virtually never comes up, it probably won't surprise you to learn the identity of the one guy in recent memory to get nailed for it:

"He's out of his mind." Yep, pretty much.

By the way, we can go back even further for some rarely seen footage of Jacques Plante leading a rush through the neutral zone – and being familiar enough with the rulebook to dish the puck off just before hitting the red line.

You're not allowed to disagree with the referee

Fans know that there's an unsportsmanlike conduct penalty in the books for abuse of officials, one that referees can use to hand a minor penalty or even a ten-minute misconduct to players who cross the line. But where is the line? Is it swearing? Personal abuse? Mom jokes?

Luckily for us, the rulebook does offer an explanation as part of Rule 39, Abuse of Officials. And it's, uh, a little more strict than you might expect.

Rule 39.2 lists the various things a player could do to earn a penalty, and it covers most of what you'd expect to find. No profane language (39.2ii), no banging the boards with your stick (39.2iii), no leaving the bench to argue a call (39.2iv). Pretty standard stuff, really.

But then there's 39.2i, which calls for a minor penalty against "any player who challenges or disputes the ruling of an official."

That's it. That's the whole rule. According to the rulebook as written, players are supposed to get two minutes for unsportsmanlike conduct each and every time they so much as dispute a call. Say "I didn't do it"? Two minutes. Shake your head? Two minutes. Look vaguely confused for a second? Two minutes.

Needless to say, the rule isn't called that way – thankfully, today's referees have a slightly thicker skin than the rulebook gives them credit for. But then next time you see a guy heading to the box while expressing even the slightest disagreement, remember: Technically, he's getting away with a penalty.

When a deadline isn't a deadline

Every year, we all gather around our TVs and computers on Trade Deadline Day, waiting for the final flood of deals to cross the wire. Then, right at 3:00 ET, the countdown ends, some sort of buzzer sounds, and that’s it for another year. No more trades are allowed for the rest of the season.

Except that they are. There’s actually nothing in the rules (or collective bargaining agreement) that says teams can't make trades after the deadline has passed.

You’re waiting for the “but” here, and it’s a pretty big one: But any player traded after the deadline can’t play in the NHL for the rest of the season. In almost every case, that’s going to be, quite literally, a deal-breaker.

But there are at least a few scenarios where a post-deadline trade could still make sense. One would involve the trading of an injured player who was already out for the year, like last year’s Evander Kane deal. Trades for minor leaguers would work too, as would those involving draft picks. And maybe two teams that were already out of playoff contention would just go ahead and make a deal anyway – shutting a few players down for a couple of weeks wouldn’t be the end of the world if you’re already looking ahead to next year. It could even be a sneaky way to tank for better lottery odds.

This rule, or lack thereof, is the reason why teams that are eliminated from the playoffs often make trades while the postseason is still going on – they don't have to wait for trading to resume, because it never actually stops. And there have been examples of teams making post-deadline player trades while the regular season was still in progress, although those moves were so minor that barely anyone noticed.

But you’d have to think that eventually, we could see a bigger deal get made in the days or weeks after the deadline. And it will be great fun, because fans who thought that wasn’t allowed will lose their minds.

Goalies can change on the fly

Sometimes, finding an odd rule will lead to a follow-up question, which leads to another odd rule, and so on down the rabbit hole. That's what happens when you start with a simple enough question: Can a goaltender who's on the bench jump on and rejoin the action while a play is still going on?

The short answer: Not always. While it won't come up in the playoffs, there's a little known rule that applies to the regular season only and prevents a goaltender who's been pulled for an extra attacker during overtime from re-entering play on the fly. It's there to close a loophole to another weird rule, one that takes away a team's loser point for an overtime loss if they've pulled the goalie.

The reason for that rule's existence is complicated, and we won't get into it here. But it leads to a bigger question: Does this mean goalies are allowed to jump back into the play the rest of the time? Yes, as it turns out, and as good-old Ilya Bryzgalov demonstrated a few years ago.

By now, you're probably wondering about the next logical link in the chain: Are goaltenders allowed to change on the fly? As in, could one goaltender head to the bench and leave the ice while his backup hops on and takes over, all while play is still going on? While it's hard to imagine a situation where it would make any sense to do that, the answer is that yes, it's technically allowed in the rulebook. And amazingly enough, it really has happened.

Those are the 1992 Penguins, who had apparently decided to switch goalies every five minutes to keep both fresh for the playoffs. I'm not sure what's more shocking: that the coach behind this bizarre move was the legendary Scotty Bowman, or that Mike Keenan didn't beat him to it.

Players can be forced to officiate their own game

Every once in a while, an official gets hurt or becomes ill during a game and can't continue. The rulebook covers how to handle this situation in section 31.11, spelling out how the responsibilities will be divided up among the remaining officials and whether an available backup should be brought into the game.

But what happens if the officials don't show up at all? That's also covered in the rule, which lays out what happens if, "through misadventure of sickness," the officials are a no-show. And the answer is that things get weird.

The first step is that the league tries to find alternate officials. If they can't, it falls to the two teams to agree on a neutral party. And if that doesn't work, then each team appoints one player, and those players officiate the game.

Yes, really.

And, believe it or not, the rule has actually been used at the NHL level. In 1983, a snowstorm delayed the arrival of the referee and one linesman at a game between the Whalers and Devils. With only one official on hand, and no qualified substitutes in the building, New Jersey's Garry Howatt and Hartford's Mickey Volcan were told to don the stripes. Volcan even kicked Ron Francis out of a faceoff.

The situation was short-lived; the missing officials arrived in time for the second period, and the rule has never come into play again since. But it's still on the books, waiting for the day that some future officiating crew falls victim to "misadventure".

At the rate things are going, let's just pencil that in for Thursday.

Sean McIndoe has been writing about the NHL since 2008, most recently for ESPN and Grantland. He spends most of his time making jokes on twitter, where you may know him as @downgoesbrown. He appears weekly on TheHockeyNews.com.