The politeness markers please, thank you, and sorry provide a raft of problems for lexicographical treatment. Grammatically, they fall between categories. As pragmatic elements, they defy easy definition, and variations in their usage are subtle. Few words are prescribed so vigorously as politeness markers ("always say please and thank you"), yet they do not fit the stereotype of a prescription, in that there is no proscription. This study investigates how please, thank you, thanks, and sorry are treated in thirteen monolingual dictionaries of English, finding variation in (a) the extent to which their interactional functions are covered, (b) the types of information contained in definitions, and (c) the (sometimes very subtle) ways in which information about the potential (im)polite effects of these words is communicated. Learner dictionaries generally provide more explicit information about the polysemy of these expressions, while traditional American lexicography provides much less useful information, in part because of a tendency to define interactional word senses using similar formulae to those for denotational senses. The best definition practice emphasizes the actions the words perform and the contexts in which the actions take place.