The Swedish championship is celebrating its 100th anniversary this season.
The Initiative
To honor this milestone, the Allsvenskan (the league's name) has decided that one month of the competition will be played with each club's historic jerseys. This is to give a retro flavor to all the matches.
It is the first competition to implement such an idea.
Ongoing Research
Teams have delved into their archives to find historic jerseys and reproduce them faithfully.
This occasion is a great opportunity to strengthen the clubs' legacy with their past and could prove to be a very successful marketing operation.
According to the website FootyHeadlines, the user @gentle_wong created the graphic designs that the teams then used to model their playing kits.
(Cover image taken from the X profile of @gentle wong)