Content and Language Integrated Learning (CLIL) describes the teaching of non-language subjects through a foreign language, typically in mainstream school education. One of the big advantages of CLIL is that it helps school students to learn to use a foreign language for professional and academic purposes, alongside their native language. This ability encompasses both competences in doing the subject, including acquiring relevant knowledge, and in using the appropriate language. The term to describe this ability is bi/multilingual disciplinary literacies. Our research network encompasses expertise from various fields, including language education, CLIL, subject education, digital media, and multilingual schools, to gain a comprehensive understanding of bi/multilingual disciplinary literacies More precisely, this Action unites researchers and teacher educators from across Europe and international partners in Canada and Hong Kong with a view towards developing a common research agenda on bi/multilingual disciplinary literacies in CLIL. The specific objectives include providing surveys of CLIL practice with regard to bi/multilingual disciplinary literacies, developing standardized research tools and training resources, identifying best educational practices and disseminating our insights to educational, academic, industry, and public stakeholders. These activities are organised in five distinct Working Groups.