CrescoData » Help Center » CrescoData Commerce Connect Platform » What is The CrescoData Mapping Language (CML)? Generic selectors Exact matches only Exact matches only Search in title Search in title Search in content Search in content Search in excerpt Post Type Selectors Hidden Hidden What is CrescoData Mapping Language (CML)? CML is CrescoData’s in-house developed mapping language. This is a universal language for product and order data.