ENThe article briefly discusses one of the major problems of prescriptivism: the conception of grammatical accuracy of language phenomena, in particular n their accuracy as a codification criterion in Lithuanian fiction texts. In Lithuania there is a valid benchmark system for evaluation of the linguistic accuracy, provided in the notebooks of iSpeech Tipsi, which is not completely clear, particularly the controversial understanding of an avoidable phenomenon of the language. It can be considered as a mistake and, on the other hand, not as a mistake but a language option, even though low-prestige. The research shows that the main standard variants are used in the fiction style more than the irregular ones. This can be determined by several reasons: first, the authores maintained dialect, second, active usage of the main options in the standard language, and third, the prescriptive approach. The validity of the stylistic motivation in the fiction style is still problematic; it is still being treated more subjectively than objectively.