From the U.S. State Department: 

Venezuela’s child protection law mandates that minors (under 18) who are citizens or non-citizen residents of Venezuela and who are traveling alone, with only one parent, or with a third party, must present a copy of their birth certificate and written, notarized authorization from the absent parent(s) or legal guardian, specifically granting permission to travel alone, with one parent, or with a third party. This authorization must reflect the precise date and time of the travel, including flight and/or other pertinent information. Without this authorization, immigration authorities will prevent the child’s departure from Venezuela. The Venezuelan government no longer recognizes blanket or non-specific travel authorizations. When a parent is deceased, a notarized copy of the death certificate is required in lieu of the written authorization. If documents are prepared in the United States, the authorization and the birth certificate must be translated into Spanish, notarized, and authenticated by the Embassy of Venezuela or a Venezuelan Consulate in the United States. If documents are prepared in Venezuela, only notarization by a Venezuelan notary is required. A permission letter prepared outside Venezuela is valid for 90 days. A permission letter prepared in Venezuela is valid for 60 days.