IEC 61400-26-1:2011(E) defines generic information categories to which fractions of time can be assigned for a wind turbine generating system (WTGS) considering internal and external conditions based on fraction of time and specifying the following: - generic information categories of a WTGS considering availability and other performance indicators; - information category priority in order to discriminate between concurrent categories; - entry and exit point for each information category in order to allocate designation of time; - informative annexes providing various examples.