In 1990, a fixed conventional value R K-90 = 25 812.807 Ω was defined for use in resistance calibrations worldwide. ‍ On 16 November 2018, the 26th meeting of the General Conference on Weights and Measures decided to fix exact values of h (the Planck constant) and e (the elementary charge), superseding the 1990 conventional value with an exact permanent value (intrinsic standard) R K = ⁠ h / e ⁠ = 25 812.807 45... Ω. ‍