IUCN Red List Categories & Criteria Released Version 3.1 (2d ed.)

This month, the International Union for the Conservation of Nature (IUCN), "the world’s oldest and largest global environmental organization," released its, Red List Categories and Criteria, version 3.1, second edition (2013). The 38-page publication is available here, as a downloadable pdf. According to the abstract,

[t]he IUCN Red List Categories and Criteria are intended to be an easily and widely understood system for classifying species at high risk of global extinction. The general aim of the system is to provide an explicit, objective framework for the classification of the broadest range of species according to their extinction risk.