Book excerpt: This manual is a supplement to the Voluntary Guidelines on the Marking of Fishing Gear (VGMFG; FAO, 2019), and provides practical instructions on marking methods for the main types of fishing gear in order to identify ownership. The marking of fishing gear contributes to sustainable fisheries, improving the state of the marine and freshwater environments by combating, minimizing, and eliminating abandoned, lost or otherwise discarded fishing gear (ALDFG); it also facilitates the identification and recovery of such gear. In addition, fishing gear marking supports fisheries management and can be used as a tool in the identification of illegal, unreported and unregulated (IUU) fishing activities. This manual is intended to assist fisheries managers, fishing gear manufacturers and the fisheries sector to meet the relevant international, regional or national obligations for gear marking. More specifically, it enables all stakeholders to comply with the specific gear marking requirements outlined in the FAO Code of Conduct for Responsible Fisheries, as well as in other international instruments and agreements. Organizations or parties concerned with, or actively addressing the issue of ALDFG may also find the information in this publication useful.