ISO 8843:2005 establishes a system for identifying crimp-removable contacts for electrical connectors. The system specified in this International Standard consists of two colour bands around the external diameter of the crimp barrel and, for thermocouple or high-temperature contacts, of additional letters or of a colour point; the system, however, does not preclude further means being used to identify additional parameters, such as cable size and material.

This contact identification system applies, when specified, to ISO standard contacts. The use of the system is recommended for contacts of both the preferred and non-preferred types. In contacts of the preferred type, the contact active portion and the wire gauge accepted by the contact barrel have the same size. In contacts of the non-preferred type, the size of the active portion of the contact differs from the wire gauge accepted by the crimp barrel.