Confidence is limited because of definitional issues regarding how to classify and measure a drought, a lack of observational data and the inability of models to include all the factors that influence droughts. (dotearth.blogs.nytimes.com)
This technical document provides background on definitional issues related to reducing emissions from deforestation in developing countries. (uncclearn.org)
Still, most organisations will choose for a wider rule, covering any belief that might upset anyone, but leading to possible definitional issues: what is a manifestation of a particular philosophy? (europeanlawblog.eu)