Subgroup
A subgroup is a set of IG or TR genes (C-GENE, V-GENE, D-GENE , J-GENE) which belong to the same group, and which, in a given species, share at least 75% identity at the nucleotide level (and in the germline configuration for V, D, and J genes).
The 'subgroup' concept is part of the 'CLASSIFICATION' concept of IMGT-ONTOLOGY[1]
Reference:
[1] Giudicelli, V. and Lefranc, M.-P., Bioinformatics, 15, 1047-1054 (1999)
PMID:10745995,
LIGM:221 