Prometheus supports this as of 3.0 but Mimir does not support it still.

If UTF-8 is enabled, some tests will need work:

• TestLabelValuesCardinalityHandler_ParseError
• ...

UTF-8 is specifically disabled in different places by setting model.NameValidationScheme = model.LegacyValidation in init functions.

Related issues:

• Epic: Implement UTF-8 character support for label and metric names prometheus/prometheus#13095
• chore: deprecate X=Mimir-SkipLabelNameValidation once UTF-8 is supported #9457