The present study addresses primarily the question of how vulgarisms are treated in various dictionaries, classifying taboo words into four main classes (etymological, euphemistic, terminological, and informal/vulgar). The main focus here is on sexual vulgarisms, as sexuality can be regarded as a multifaceted taboo established by various factors such as religion, psychology and the like. Our claim is that there exist certain taboo mechanisms within the lexicographic process that influence the design of particular dictionary entries. Supported by original research, our study illustrates how these mechanisms apply in the Large German-Czech Academic Dictionary and the Academic Dictionary of Contemporary Czech. Challenges in the description of vulgarisms, e.g. orthography, definition or exemplification, are presented. It is posited that the user aspect must be given enhanced status within the dictionary-making process and that lexicographers often have to base their decisions on common sense rather than a general methodology that often cannot account for various special cases and exceptions.