Extra "guest" teams are occasionally invited at the discretion of the organizers: Israel was invited in 2001, Belarus in 2004 and 2014, Belgium in 2005, South Africa in 2011, the Netherlands in 2015 and Ireland in 2021. Responsibility for organizing the contest circulates among the regular participants.
Occasionally, additional teams are invited to participate in the contest by the organizers, with Israel being invited in 2001, Belarus in 2004 and 2014, Belgium in 2005, South Africa in 2011, the Netherlands in 2015 and Ireland in 2021. The organization of the competition shifts among the regular participants.