4. The Authority may adopt regulatory measures in relation to the collection, use, retention and disclosure of subscriber information and communications including, but not limited to, requiring service providers to retain or prohibiting service providers from retaining certain information relating to subscribers, including information on billing, for or after a specified period of time. 5. A service provider shall not intercept, monitor, alter or modify the contents of a communication, except as provided in the present Decree-Law or in any other law. 6. Nothing in the present Decree-Law shall be interpreted to prohibit or limit the rights vested by the laws of Timor-Leste in the competent law enforcement bodies and the courts related to the access of confidential information or communications of subscribers. 7. The making of regulatory measures pursuant to this article shall be subject to paragraph 4 of article 19. Article 50 Standard terms and conditions 1. A service provider supplying public telecommunications services shall: a) Establish standard terms and conditions that are reasonable and readily understandable for the provision of public telecommunications services; b) Establish complaint and dispute procedures that are simple, fair and reasonable and allow for an impartial and quick treatment and resolution of complaints, and that also define the applicable conditions for refunds and compensation; c) Publish such terms and conditions, procedures and remedies on its website and make them available at points of sale; d) Submit such terms and conditions, procedures and remedies to the Authority upon request; e) Make such changes to the terms and conditions, procedures and remedies as the Authority requires; and f) Comply with such terms and conditions, implement such procedures and establish the conditions for reimbursement and compensation as required by the Authority. 2. The imposition by the Authority of requirements pursuant to subparagraphs e) and f) of the preceding paragraph shall be subject to paragraph 4 of Article 19.