title: Bounded Context for Master and Reference Data in DDD
body: <p>I am relatively new to the concept of DDD and have found there are plenty of examples which explain how a bounded context should be defined for relatively simple scenarios, but one area that doesn't seem to be covered is master data and reference data.</p>
  
  <p>The types of reference data I'm referring to would currency codes, country codes, and units of measurement, which would be used to ensure only valid values are used. </p>
  
  <p>The types of master data I'm referring to would be entities such as customers and products where there is no requirement for different bounded contexts to have their own perspective of the entity. I understand that in some scenarios the customer entity in an invoicing bounded context would be different the customer entity in a shipping bounded context, but for the purpose of this question we can assume that both invoicing and shipping need exactly the same customer data.</p>
  
  <p>My questions is in an application that has multiple bounded contexts (such as an ERP system) should master data and reference data be defined in a common bounded context or should these entities be duplicated in each bounded context even when they would contain exactly the same data?</p>