This is the codebook created for the analysis of focus group interview data collected as part of the DETECT project. In particular, nine interviews were conducted with primary and secondary school teachers in Finland, Italy, Spain and the UK in order to explore their perceptions of critical digital literacies and how these are manifested in their practices. The interviews were organised and conducted by the researchers in the respective local HEIs between February-June 2020. A total of 7 focus-groups interviews took place with a total number of 39 participating teachers (7 from Finland, 6 from the UK, 9 from Spain and 17 from Italy). The interviews were conducted both face to face (schools in Spain) and online (schools in Finland, Italy and the UK) due to pandemic-related restrictions imposed shortly after the start of the data collection period. The collected data were read and segmented and all interview excerpts relating to the Critical Digital Literacies framework sub-dimensions were marked and chosen for the analysis. The total number of marked segments was 666 in all nine focus group interviews. To ensure the reliability of the analyses, the researchers translated and collected a representative sample of codings (n=117 out of 666) for each sub-dimensions from each school and these were examined by all researchers in several consensus meetings and the final criteria for each sub-category were constructed together based on those discussions. This dataset accompanies the intellectual outputs of the DETECT project, including amongst others this report: Gouseti, A., Bruni, I., Ilomäki, L., Lakkala, M., Mundy, D., Raffaghelli, J., Ranieri, M., Roffi, A., Romero, M. and Romeu, T. (2021) Schools’ perceptions and experiences of critical digital literacies across four European countries - DETECT Report 2. Accessed at: http://doi.org/10.5281/zenodo.5070394 Acknowledgement This project was funded by Erasmus+, KA2. Project Reference: 2019-1-UK01-KA201-061508.