<PackageReference Include="System.Diagnostics.EventLog" Version="10.0.0" />

System.Diagnostics.Eventing.Reader.EventOpcode

public sealed class EventOpcode
Contains an event opcode that is defined in an event provider. An opcode defines a numeric value that identifies the activity or a point within an activity that the application was performing when it raised the event.
namespace System.Diagnostics.Eventing.Reader { public sealed class EventOpcode { public string DisplayName { get; } public string Name { get; } public int Value { get; } } }