We've seen teams retire jersey numbers, but we've never seen the actual NBA retire a number altogether.
Well, until now.
In a league-first, the NBA has formally retired Bill Russell's number 6 jersey following the legend's recent death.
An 11-time NBA champion, Russell is the most decorated played in the sport's history.
Throughout his career, the Boston Celtics icon also used his platform to be a strong voice for social justice.
Sadly, at the age of 188, he passed away – leaving behind a bunch of fond memories which will live with basketball fans for a long, long time.
And to pay tribute to Russell, as well as celebrate his wonderful life, the NBA has not only decided to retire his famous number but also include a shamrock-shaped patch on the jersey of every player this upcoming season.
It's understood the number 6 will feature on every court too – similar to what was done with Kobe Bryant's number 8 and 24 after his tragic passing.
Interestingly, the current crop of players who don the number - including LeBron James - will not have to find new jersey digits.
“Bill Russell’s unparalleled success on the court and pioneering civil rights activism deserve to be honoured in a unique and historic way,” NBA commissioner Adam Silver said in a statement.
“Permanently retiring his No. 6 across every NBA team ensures that Bill’s transcendent career will always be recognised.”
Russell joins an elite list of legendary athletes to have had their jersey numbers retired by the leagues they played in.
Major League Baseball retired Jackie Robinson's number 42 back in 1997, while the NHL has vowed that no other player will wear Wayne Gretzky’s number 99 after he hung up the skates.
Some sports franchises in the United States have retired their number 12 in honour of their loyal supporter base, which they dub "the twelfth man".
A bunch of NBA legends paid tribute to Russell following his passing.
Chicago Bulls great Michael Jordan lead the chorus of big-name stars who sent their condolences via social media.
“Bill Russell was a pioneer—as a player, as a champion, as the NBA’s first Black head coach and as an activist,” Jordan wrote.
“He paved the way and set an example for every Black player who came into the league after him, including me. The world has lost a legend. My condolences to his family and may he rest in peace.”
Featured Image Credit: Alamy/Instagram/realbillrussell