Interpretive front-of-pack food labelling (FOPL) is a policy priority for promoting healthy diets. Research evidence indicates that consumers have a reasonable understanding of interpretive FOPL systems and their understanding improves with label familiarity and consistency within the market. A government-endorsed interpretive FOPL policy was found in 15 Member States of the WHO European Region, and this report summarizes the evidence on their development and implementation to support policy-makers in navigating these processes. Most existing policies have been implemented under voluntary arrangements, with variable penetration into the marketplace. Policy development that is led by government and based on formative research, and that engages stakeholders and the public, is most likely to lead to acceptable, credible and effective policies. FOPL implementation is best supported by policy provisions that encourage widespread uptake of the system and allow for formal evaluation of both implementation and impact.