IMediaCDM::GetCDMCustomJSONPrefixes

Obtains the CDM system's preference on how attributes and text properties should be prefixed in the JSON string passed to GetCDMCapabilitiesForScheme(..., InAdditionalElements) or in the [FCDMCandidate.AdditionalElements](API\Plugins\ElectraCDM\IMediaCDM\FCDMCandidate\AdditionalElements).