From 1961 to 1994 the ATCM generally met once every two years, but since 1994 the meetings have occurred annually. Measures, Decisions and Resolutions, which are adopted at the ATCM by consensus, give effect to the principles of the Antarctic Treaty and the Environment Protocol and provide regulations and guidelines for the management of the Antarctic Treaty area and the work of the ATCM. Decisions, which address internal organizational matters of the ATCM, and Resolutions, which are hortatory texts, are not legally binding on Contracting Parties. In contrast, Measures are legally binding on the Consultative Parties once they have been approved by all Consultative Parties. Only the Consultative Parties take part in decision-making. Other participants in the meeting, however, may contribute to the discussions.