details, such as provision for the payment of costs in advance, can be the subject of bilateral negotiations. "(a) To appear in proceedings in relation to a criminal matter in the Requesting State unless that person is the person charged; or "(b) To assist in the investigations in relation to a criminal matter in the Requesting State. "2. The Requested State shall invite the person to appear as a witness or expert in proceedings or to assist in the investigations. Where appropriate, the Requested State shall satisfy itself that satisfactory arrangements have been made for the person's safety. "3. The request or the summons shall indicate the approximate allowances and the travel and subsistence expenses payable by the Requesting State. "4. Upon request, the Requested State may grant the person an advance, which shall be refunded by the Requesting State. "ARTICLE 15 "Safe conduct 131/ "1. Subject to paragraph 2 of this article, where a person is in the Requesting State pursuant to a request made under articles 13 or 14: "(a) That person shall not be detained, prosecuted, punished or subjected to any other restrictions of personal liberty in the Requesting State in respect of any acts or omissions or convictions that preceded the person's departure from the Requested State; "(b) That person shall not, without that person's consent, be required to give evidence in any proceeding or to assist in any investigation other than the proceeding or investigation to which the request relates. "2. Paragraph 1 of this article shall cease to apply if that person, being free to leave, has not left the Requesting State within a period of [15] consecutive days, or any longer period otherwise agreed on by the Parties, after that person has been officially told or notified that his or her presence is no longer required or, having left, has voluntarily returned.
**Analysis**
The text appears to be discussing international cooperation and mutual assistance between states in the context of criminal investigations and proceedings. The language used is formal and treaty-like, suggesting a legal or institutional framework. The content focuses on the treatment of individuals in one state at the request of another, including issues related to witness testimony, detention, and travel expenses. These themes suggest a connection to international law and cooperation, rather than economic development, natural resources, or other categories.

**Category**
International law, Humanitarian aid and relief