A/HRC/27/50 guaranteeing the effective accountability of PSCs and their personnel, it is essential that human rights-based vetting mechanisms as well as mandatory legal training with reference to the relevant international human rights and humanitarian law and standards be introduced. Such training in human rights standards is imperative and should form part of the overall mandatory criteria for obtaining a licence to operate and for subsequent licence renewals. 71. The study indicates that, although several national laws provide for the establishment of a government authority responsible for granting licences to PSCs, very few of the States reviewed require or grant power to the said authority to keep a centralized register of licences that have been awarded. States’ obligation to keep such a register may assist in maintaining oversight of PSC operations and the conduct of PSC personnel. 72. The Working Group hopes that the study of national legislation on PMSCs will enable it to identify good practices that would contribute to its development of guidance for Member States on how to regulate PSCs effectively and ensure the enjoyment of the right to security by all. For instance, the regulation of the export of security (and military) services is an example of good practice, which States must consider addressing within their regulatory frameworks. Other good practices include the mandatory requirement for PMSCs to have a sound organizational structure coupled with an effective post accountability system that addresses not only their activities, but also the conduct of their personnel, and the requirement for all alleged offences or violations committed by PMSCs and/or their personnel to be reported to the police or other law enforcement agents. 73. Notwithstanding the good practices that may be identified by the Working Group in the course of its study of national legislation on PSCs and despite the detailed provisions on permitted and prohibited activities, there are still regulatory gaps relating to issues such as the acquisition of weapons and trafficking in arms by PMSC personnel and their consequences and divergent approaches to the use of force and firearms in the course of duty. Taking into account the nature of PMSC activities and the potential participation of PSC personnel in combat and mercenary-related activities, as well as the likelihood that PMSC personnel carry and use weapons, the lack of regulation creates potential risks to human rights. An international convention could provide standard rules and methods on acquiring, exporting, importing, possessing and using weapons and would ensure that PMSC personnel worldwide are also held accountable for illegal acquisition of weapons, illicit trafficking in arms and prohibited use of force. 74. The study highlights the lack of clear regulations on oversight by the authorities and accountability of actors in the PMSC industry. Legislation is particularly silent on how the conduct of PSCs or PMCs is arbitrated during potential events of unrest or armed conflict. An international convention covering issues such as licensing, authorization, selection and training of PMSC personnel would promote implementation at the national level of common and consistent regulations that would ensure effective accountability and the availability of remedies for violations. 75. The Working Group reiterates its view that a comprehensive, legally binding international regulatory instrument would be the best way to ensure adequate protection of human rights. In that regard, the Working Group welcomes the work of the intergovernmental working group established by the Human Rights Council with a view to considering the possibility of an international instrument for the regulation of PMSCs; it encourages all States to participate actively in that process. 20