Statement 1 is correct. Section 19(1) of the RTI Act states that any person who does not receive a decision on a request for information within the specified time limit, or is aggrieved by a decision of the PIO, may prefer an appeal to the first appellate authority (an officer senior in rank to the PIO) within 30 days. This "person" is typically the applicant. Statement 2 is incorrect. The right to appeal is primarily for the person seeking information or a third party whose information is being disclosed. A person from within the Public Authority, in their official capacity, is involved in the process of providing information, not appealing against the decision regarding an application by an external party. Statement 3 is correct. Section 19(3) read with Section 11 of the Act allows a third party (a person other than the applicant) whose information is proposed to be disclosed by the PIO to appeal against the PIO's decision to disclose such information. This appeal is made to the first appellate authority before the information is actually disclosed.