In addition to competitors, competition associations with the right to sue can also enforce unfair competition claims on the market. However, one of the prerequisites for this is that the association must include a significant number of companies that sell goods or services of the same or a related type on the same market. The IDO Association was unable to sufficiently demonstrate and prove this in proceedings before the Regional Court of Rostock, with the result that the court rejected the corresponding legal standing. The warning issued was therefore unlawful and the costs of the proceedings were imposed on the competition association (Regional Court of Rostock, judgment of May 2, 2019, Ref. 5a HKO 112/18).