Employment law: Validity of wage claims and contractual remuneration entitlements in labor disputes

The Federal Labor Court (BAG) reversed the lower labor court's decision, dismissing the employee's appeal and leaving the first-instance judgment in force, thereby awarding the employer the litigation costs for both the appeal and revision. The dispute involved a wage claim where the employee challenged the calculation of remuneration, specifically contending for additional payment based on a particular employment arrangement or contractual entitlement, while the employer disputed the validity or applicability of such claims. The decisive legal basis centered on the interpretation of the employment contract and the application of statutory wage law, with the court determining that the employee failed to substantiate a valid claim for the contested remuneration, resulting in a complete rejection of the plaintiff's suit.