The IDENTIFICATION axiom of the Formal IMGT-ONTOLOGY or IMGT-Kaleidoscope postulates that molecules, cells, tissues, organs, organisms or populations, their processes and relations, have to be identified. The IDENTIFICATION axiom has generated the concepts of identification which provide the terms and rules to identify an entity, its processes and its relations. In molecular biology, the concepts of identification allow to identify the molecular components, the molecules, their processes and their relations at the genome, transcriptome, proteome, structure and function levels.