Using Language Management Theory (Nekvapil and Sherman, 2009), this study examines Facebook pages as space and tool of conduct-toward-language, centering on humor use. The explored Czech language is not subjected to elaborate formal language policy. Standard written Czech is fostered in daily humorous Facebook interactions, especially those which correlate with humor's superiority theory (Billig, 2005). Two pages indicating their connection to the notion of “Grammar Nazis”, are analysed. As grammar here is mainly related to orthography, knowledge of which is linked to education and cultural capital, the involved practices thus constitute a social differentiation device.