Social network platforms in enterprises are an increasingly important phenomenon. Thus, the participation and content generation of users are critical aspects of the sustainable use of these enterprise social media (ESM) services. However, at the same time, organizations need to ensure the quality of user-generated content (UGC), which remains a challenge for ESM moderation. In this structured literature review, we investigate measures to identify high-quality UGC and organizational approaches to promote such UGC. We categorize our findings as textual-, content appraisal, network- and author-based measures. We follow up by assigning each measure to a motivation and localization approach. We reflect on opportunities to transfer public social media measures into an ESM environment. We conclude our examination of UGC quality by integrating the UGC quality dimension into an ESM moderation framework and by outlining implications for research and practice.