What does lex mercatoria mean?

lex mercatòria - trade law [in modern law, this concept, in addition to its main meaning, also has an additional, broader and multi-meaning: in particular, it often refers to the entire heterogeneous array of general principles and specific rules contained in domestic and international sources (including those of a recommendatory nature), including those developed by authoritative international organizations) or developed by judicial practice, as well as expressed in customs aimed at private law regulation, development and promotion of international trade and foreign economic activity].