Anti-relevant, contra-iconic but system-adequate: on unexpected inflectional changes

Several universal principles have been suggested that are supposed to limit the possible shape of inflectional systems, such as the Principle of Iconicity and the Principle of Relevance. The paper presents two case-studies which clearly falsify the expectations arising from these two principles and cry for an explanation. This has to be sought in a conflict between general principles limiting the universal degree of variation tolerated by inflectional systems and System Adequacy, namely the tendency of an inflectional system of improving its internal consistency. The result is a more economic, i.e. less costly, representation of morphological information, at the expense of the violation of the universal principles caused by contra-iconic and anti-relevant coding strategies.