The Austrian High Court judgment passed on the Lyoness General Terms and Conditions (case ref. 10 Ob 45/16i of 18 May 2018) already cite EU directives in the statement of grounds for the judgement on pages 8/9.
From the Austrian High Court judgement, 2.1.2:
Any unclear or incomprehensible contract term in the general terms and conditions or contract form is null and void according to the Austrian Consumer Protection Act (KSchG) §6 para. 3.
This legislation implements the 93/13/EEC directive of the Council of Europe of 5 April 1993 on unfair clauses in consumer contracts, thus regulating what is referred to as the transparency principle in consumer transactions.
The purpose of this legislation is to enable customers to gain reliable information on their own rights and obligations in executing a contract from general terms and conditions or contractual components.
A typical consumer shall not be deterred from enforcing his or her rights due to inaccurate or unclear representation of their contractual position or any unjustified obligations imposed on the consumer.
The transparency principle includes the recognisability and comprehensibility of a clause as well as the obligation to inform the other party of certain legal consequences.
Any consumer affected must be able to assess the resulting financial consequences based on accurate and coherent criteria to the consumer. The transparency principle always assumes the use of terms whose meanings a typical consumer can (easily) determine.