No offense to proper Bostonians or any wicked arrogant fan of the New England Patriots. But the Broncos do not want you here in Denver. The local NFL franchise did not give blood, sweat and tears all season long to surrender its home-field advantage to an invasion of loudmouths from New England. No chowderheads allowed.

“I’ve got a lot of friends back on the East Coast. … But I was a true Bronco, because I had people call me (for tickets) who said they were lifelong Patriots fans and I told them: ‘Absolutely not. You’re not getting in,’ ” former Denver safety John Lynch said Thursday.

For the AFC championship game, the home team has secured its stadium with a ticket policy that discourages Tom Brady-loving interlopers from entering the gates of Sports Authority Field at Mile High.

“Our fans remember what happened during the last AFC championship in Denver, and they didn’t like it,” Broncos president Joe Ellis said.

Call it the power of Peyton Manning. Salute the loyalty of Broncomaniacs. The stadium will be a sea of orange when Denver plays New England.

The devotion to this team has been unreal. When the Broncos were 9-2 and tied with Kansas City for first place in the AFC West, team management asked season-ticket holders to place orders on two home playoff games, at a time when even a single home playoff game was in doubt. Ninety-six percent of the team’s customers backed the faith in Manning and Co. with their hard-earned money.

“That shows how much the fans believed in this team,” Ellis said.

The Broncos, however, took one more measure in a clever attempt to ban Bostonians in Denver. When tickets were offered for the AFC championship game to the general public, there was one very strict rule: Orders were only processed to billing addresses in eight states. Colorado and Montana were included on the approved list. Massachusetts was not.

The 2,800 tickets sold out in 10 minutes to ZIP codes firmly in Broncos Country.

Consider this a lesson learned the hard way by Denver.

It has been eight, long years since the Broncos advanced to the conference championship game. After beating New England in the AFC semifinals in a game that turned on a 100-yard interception return by Champ Bailey, Denver won the right to host Pittsburgh with a trip to the Super Bowl on the line.

On a sunny, 54-degree afternoon in January 2006, everything was beautiful at the stadium, except for the ugly swarm of yellow Terrible Towels twirled by thousands of Steelers fans who purchased tickets to the game. The home-field advantage for Denver was wrecked so extensively it shook up veteran players.

“It was brutal. I’ll never forget walking out in the stadium with Champ (Bailey) as we were going out for DB drills early, before the game. We both looked at each other and said: ‘What is this?’ The problem with the Pittsburgh fans was the Terrible Towels are so visible, so it felt like there were more Steelers fans than Broncos fans,” Lynch recalled.

“You shouldn’t let that affect you. But I think it affected us. It affected our team, and the Steelers got off to a hot start. … We let a great opportunity go. It was a sickening feeling, and I think people in the Broncos organization, from that day forward, decided: ‘We can’t let this happen again.’ “

Pittsburgh quarterback Ben Roethlisberger completed his first five passes, and the Steelers scored on all four of their first-half possessions. Down 24-3 at intermission, the Broncos never recovered. The sad day was the beginning of the end for coach Mike Shanahan.

Here’s the untold reason: There were so many Pittsburgh fans in the stadium because demand for seats by Denver fans was so subdued. Despite the 13-3 regular-season record by the Broncos, approximately 30 percent of their season-ticket holders declined to reserve spots for the playoffs.

In the most direct way possible, customers of the 2005 edition of the Broncos had given Shanahan a vote of no-confidence in his ability to win a championship. The coach’s relationship with franchise owner Pat Bowlen began what proved to be an irreversible decline.

One of the most magical rides in Denver sports history was Rocktober 2007. The scrappy local baseball team refused to lose, winning 21-of-22 games en route to the World Series.

Then, the magic ended with a thud … and the ugly sound of Boston fans chanting in LoDo, as the Red Sox swept the World Series. An ill-conceived ticket policy gave access to so many loudmouth New Englanders to Coors Field that the Rockies might as well have played Neil Diamond’s “Sweet Caroline” during the eighth inning of Game 4.

Well, enough of that sorry noise.

Full of themselves after recent championships by their major-league hockey, baseball and basketball franchises, New England fans act like they invented every game.

The Broncos found an inventive way to shut them up.

In the House of Manning, there will be no chowderheads allowed.

Mark Kiszla: mkiszla@denverpost.com or twitter.com/markkiszla