While Dutch non-standard language use has been studied in oral communication (e.g. Ghyselen 2016) and private chat conversations (e.g. De Decker 2014), little attention has been devoted to non-standard language in a broad sense in online public written communication. We focus on one communicative setting, i.e. complaint management on corporate Facebook pages, since the linguistic wrapping of both consumer feedback and company responses has a considerable influence on the outcome of the interaction between both parties. In addition to providing insights for future webcare research, we aim to contribute to the general discussion on nonstandard language variation in Flanders. Based on a self-compiled corpus of approximately 300.000 words of consumer-company interactions taken from 8 corporate Facebook pages (in the fields of public transport, online retail and telecommunications), we investigate to what extent typical features of informal online communication via social media spill over into more sensitive contexts of complaint management. We do so quantitatively by mapping the presence and frequency of old and new vernacular features (Androutsopoulos 2011) in consumer-initiated posts, company replies and consumer to consumer interactions via Python-based scripts and manual filtering. The searches were based on an overarching framework of 28 old (e.g. final –t deletions) and 13 new vernacular (e.g. chatspeak abbreviations) features, which we derived from existing taxonomies (e.g. Lybaert & Delarue 2017, Taeldeman 2008, De Decker 2014, Hilte et al. 2017). Although most consumer and company messages were in large part written in Standard Dutch, fairly high frequencies were found for some of the new vernacular features (e.g. one in four consumer messages contained flooding of punctuation symbols (e.g. ?? or !!!). Consumers predominantly use new vernaculars for expressive compensation, while companies appear to have incorporated them in their responses to consumer feedback (especially emoji and English insertions) ...