Refers to enforceable legal principles and standards based on or established by the customs of a group, such as a tribe or rural community.: (GLIN) Comprehensive and uniform repetition of behavior over a long period, in the belief that such behavior is obligatory. Custom then often becomes part of international law, which may in turn lead to a custom that becomes binding even on nations not party to international: instruments. (SST--Source: International Humanitarian Law and the Geneva Conventions and University of Minnesota Human Rights Library)