The article demonstrates that official reports are policy tools that propagate meanings related to a public problem. Comparing the production of official reports in France and in Quebec about shale gas, it shows that the initial choices in terms of mandate and the organization in charge first constrained the editorial process, then that the committees’ consultation and reference practices contribute to shape the meanings of the controversy. These reports disseminate those meanings, which follow different trajectories depending on the actors able to support them in the public debate. An official report is a policy tool because of its ability to legitimize specific meanings, but it also generates unplanned outcomes such as its reuse outside the scope of its mandate.