Fig. 3From: QL4MDR: a GraphQL query language for ISO 11179-based metadata repositoriesThis sequence diagram shows the required messages between the GraphQL client (left) including the used query (box), the RESTful client (right) and the MDR server to receive the validation rules of each data element in a specific namespace. The GraphQL client needs only one query shown in the box, whereas the message amount of the RESTful client depends on the number on data elements associated with the chosen NamespaceBack to article page