Necessary meta-data for pedotransfer functions

Although pedotransfer functions have been published for more than 25 years, most published functions have very little information on the functions themselves and where they can be used. In this paper, we recommend 3 tables to accompany every published PTF so that users can decide whether they can potentially use a published PTF on their data. The first table contains the information and statistics of the training data. The second table provides information and statistics about the variable to be predicted on the calibration set. The third table contains the statistics of the validation data. Furthermore, the function should be expressed, and uncertainty measures of the function should also be included.