(b) The types of travel document that individuals have used or attempted to use to cross an international border for the purpose of trafficking in persons; and (c) The means and methods used by organized criminal groups for the purpose of trafficking in persons, including the recruitment and transportation of victims, routes and links between and among individuals and groups engaged in such rafficking, and possible measures for detecting them. 2. States Parties shall provide or strengthen training for law enforcement, immigration and other relevant officials in the prevention of trafficking in persons. The training should focus on methods used in preventing such trafficking, prosecuting the traffickers and protecting the rights of the victims, including protecting the victims from the traffickers. The training should also take into account the need to consider human rights and child- and gender-sensitive issues and it should encourage cooperation with nongovernmental organizations, other relevant organizations and other elements of civil society. 3. A State Party that receives information shall comply with any request by the State Party that transmitted the information that places restrictions on its use. Article 11 Border measures 1. Without prejudice to international commitments in relation to the free movement of people, States Parties shall strengthen, to the extent possible, such border controls as may be necessary to prevent and detect trafficking in persons. 2. Each State Party shall adopt legislative or other appropriate measures to prevent, to the extent possible, means of transport operated by commercial carriers from being used in the commission of offences established in accordance with article 5 of this Protocol. 3. Where appropriate, and without prejudice to applicable international conventions, such measures shall include establishing the obligation of commercial carriers, including any transportation company or the owner or operator of any means of transport, to ascertain that all passengers are in possession of the travel documents required for entry into the receiving State. 4. Each State Party shall take the necessary measures, in accordance with its domestic law, to provide for sanctions in cases of violation of the obligation set forth in paragraph 3 of this article. 5. Each State Party shall consider taking measures that permit, in accordance with its domestic law, the denial of entry or revocation of visas of persons implicated in the commission of offences established in accordance with this Protocol. 6. Without prejudice to article 27 of the Convention, States Parties shall consider strengthening cooperation among border control agencies by, inter alia, establishing and maintaining direct channels of communication. Article 12 Security and control of documents