MRV – Measurement/Monitoring, Reporting and Verification - is commonly understood as a series of processes to quantify GHG emission and their change over time. It is a key instrument to understand the level of emissions and the impact of actions aimed at changing emission levels. For this reason, MRV became a keyword as many developed and developing countries introduce measures to account greenhouse gas emissions and related support. However, little work has been done on clarifying what exactly MRV means and systematically documenting the implemented cases of MRV. In addition, there is a common trade-off between the simplicity and stringency of MRV. This report contributes to the further development of MRV modalities and methodologies by providing conceptual clarification of MRV and outlining 16 case studies of MRV schemes being implemented on the ground. Based on these case studies, the report identified eight key messages.