These Guidelines aim to be equally relevant for any taxon on Earth. Recent experience has shown that no two planning situations are the same. So while the principles of planning may be constant, the purpose of the planning and the circumstances, the information available and its accuracy, and other factors, all combine to make every situation unique. This then demands a planning process that is both rigorous in analysis but flexible in its application. The Guidelines are very much an evolution based on experience, rather than a fundamental replacement of the 2008 Handbook (Strategic Planning for Species: A Handbook).