The message Violation: “abstractConceptDefinitionInExtensionTaxonomy” occurs if the iXBRL file in question contains definitions for one or more abstract concepts in the extension taxonomy.
Note: ESMA states that reports SHOULD NOT contain definitions of abstract concepts. The use of SHOULD instead of MUST, means that this is a non-blocking error.
Abstract Concepts in Extension Taxonomies
Guidance 3.2.5 Definition of abstract concepts in extension taxonomies in the ESEF Reporting Manual states that it is not required to define abstract concepts in extension taxonomies. The reasoning behind this is that the abstract concepts defined in the applicable taxonomy should be sufficient.
Furthermore, ESMA discourages the use of definitions of abstract concepts in extensions taxonomies. However, should an issuer need another grouping item to reflect the structures of elements used in the annual financial report, abstract headers can be defined in the extension taxonomy.