A combined set of indicators, weighting factors and algorithms for quantification of a soil function based on the quantification of an agreed set of attributes. A proxy indicator system aims at the assemblage of a wide-ranging set of information from indicators (in fact: all required proxies) and provides a quantification protocol of a specific soil function, being as such a compromise between ease of measurement / data availability, whilst providing sufficient, if minimal, information on the attribute (set). Different proxy indicator systems may arise for one soil function, depending on requirements for a) specific spatial/temporal scale, b) agricultural objective, soil texture and climate conditions, and c) the required performance (reduction of uncertainty) and available budgets to harness the proxy indicator system with reliable data and models. It is the objective of LANDMARK to produce proxy indicator systems which are at least partially overlapping (see ‘nestedness’).