Romanised Cantonese, mixed with English, in the context of the Hong Kong protests, has been used to flummox non-Cantonese speakers and automatic translation machines, and weed out infiltrators and trolls. It has been hailed by some as a new form of cryptic online messaging. It is, however, a continuation of a long-standing language practice. Since the end of the 20th century, young Hongkongers – in internet chat rooms, text messages and on social media – have been romanising Cantonese for greater efficacy. In 2015, this mixed code received a name, Kongish, and was bestowed a Facebook page, Kongish Daily, which became an instantly popular public platform. The use of a romanised mixed code on social media has promoted the English calque “add oil”, from the Cantonese “ ga yau ”. The romanisation of Chinese language varieties has a long history, dating back to Italian Jesuit priest Matteo Ricci’s late-16th century Portuguese-Chinese dictionary. For Mandarin, well-known systems include Wade-Giles, which was devised by British diplomat Thomas Francis Wade in the mid-19th century, and Yale, which was created at Yale University, in the United States, during World War II to facilitate communication between American military personnel and their Chinese counterparts. But it is Hanyu Pinyin – developed by Mao Zedong’s Committee for the Reform of the Chinese Written Language in the late 1950s and adopted as the standard in 1982 – that has superseded all others. Southern Min varieties, such as Taiwanese Hokkien and Amoy Hokkien, use Peh-ōe-jī (“vernacular writing”), a modified Latin alphabet with some diacritics developed by 19th century Western missionaries working amongSoutheast Asia’s Chinese diaspora. For Cantonese, two main systems are used in scholarship – Yale and Jyutping. Yale was developed for the 1958 Speak Cantonese textbook, where tones are represented by accent marks. Jyutping was designed by the Linguistic Society of Hong Kong in 1993. The system used by the Hong Kong government – primarily for naming streets and places – is based on neither of these, but on the Standard Romanisation developed by Christian missionaries in South China in 1888. Mao may have wished for pinyin to replace characters, but it is the shared identity and norms and the freedom to create among Hongkongers that has harnessed romanisation to empower and communicate.