This paper presents implementations of generative management method for morphological variation of query keywords. The method is called FCG, Frequent Case Generation. It is based on the skewed distributions of word forms in natural languages and is suitable for languages that either have fair amount of morphological variation or are morphologically very rich. The paper reports implementation and evaluation of automatic procedures of variant query keyword form generation with short and long queries of CLEF collections for English, Finnish, German and Swedish. The evaluated languages show varying degrees of morphological complexity.