Analogue indicating measuring instruments and accessories; Part 1 - general requirements, Part 8 - accessories.
The IEC 60051 series applies to direct acting indicating analogue electrical measuring instruments and their accessories. Part 1 gives definitions and general requirements common to all parts; Part 8 gives particular requirements for accessories (including shunts and series resistors) within the meaning of IEC 60051-1:2016, with Annex A classifying nonconformities in tests.
Digital instruments and PMDs are outside its scope (IEC 61557-12 explicitly excludes analogue instruments according to IEC 60051).
A shunt with an accuracy class according to IEC 60051-8 provides a defined current-measurement chain error when used with an analogue meter - a parameter needed for the measurement uncertainty budget in a substation switchboard.
