The group, which occupies part of the north curve of Celtic Park, organises choreographed displays known as tifos and encourages singing during matches.
In recent years, the Green Brigade has been increasingly vocal on non-football related issues.
Some members have had their season tickets withdrawn by Celtic after a “serious escalation” in unacceptable behaviour.
The Green Brigade is made up of about 1,000 Celtic fans – 250 of whom are officially registered with Celtic as being part of the Green Brigade Supporters’ Club.
This is how Celtic will know which season tickets to suspend during the newly-announced indefinite ban.
The group has season tickets in the Rail Seating Section- essentially a standing area – of the north curve of Celtic Park.
The Green Brigade was formed in 2006 in an attempt to improve the atmosphere during match-days.
In addition to the choreographed banner displays in the stands (known as tifos), the group often bring drums, encourage singing and use pyrotechnics.
According to the group’s own website, the Green Brigade is “notoriously difficult for fans to join”.
Members often keep their identities hidden, with their faces being blurred in photos posted online.
In the same vein, the group recently said that no members have or will speak to the “mainstream British press” about “the current situation” – referencing the withdrawal of tickets.
