<PackageReference Include="System.Configuration.ConfigurationManager" Version="9.0.4" />

SpecialSettingAttribute

public sealed class SpecialSettingAttribute : Attribute
Indicates that an application settings property has a special significance. This class cannot be inherited.
namespace System.Configuration { [AttributeUsage(AttributeTargets.Class | AttributeTargets.Property)] public sealed class SpecialSettingAttribute : Attribute { private readonly SpecialSetting _specialSetting; public SpecialSetting SpecialSetting => _specialSetting; public SpecialSettingAttribute(SpecialSetting specialSetting) { _specialSetting = specialSetting; } } }