It standardizes how magnetization curves are measured (using RMS for both axes), reducing confusion that existed when different standards used peak values.
It's in the definition of "rated voltage factor" (e.g., 1.2 or 1.9 continuous). That little factor tells you whether the VT was designed for a solidly grounded system (1.2) or an ungrounded/resonant system (1.9). One number tells a whole story about system design philosophy. 61869-2
Failure to adhere to these standards can lead to "false tripping" (where a relay shuts down power unnecessarily) or, worse, a failure to trip during a real electrical fault, potentially causing catastrophic equipment damage. It standardizes how magnetization curves are measured (using