IT-supported knowledge repositories are an important part in Knowledge Management (KM) work. The success of an IT-supported knowledge repository is dependent on what is stored in the repository and hence the ability to capture the right knowledge is a key aspect. Therefore, to increase the quality in an IT-supported Knowledge Repository, the identify activity, which starts the capture process, must be successfully performed. While Critical Success Factors (CSF) for KM and KMS are frequently discussed in the literature, there is a knowledge gap concerning CSF for this specific knowledge capture activity. Based on an interpretive field study and a literature review, this paper proposes and characterizes CSF for the identify activity. For example, we highlight the importance of having organizational knowledge about what knowledge to capture and where to find it, i.e. having knowledge about potential sources of knowledge.