Umbraco-CMS/src/Umbraco.Core/Persistence/DatabaseAnnotations/NullSettings.cs

namespace Umbraco.Core.Persistence.DatabaseAnnotations
{
    /// <summary>
    /// Enum with the 2 possible Null settings: Null or Not Null
    /// </summary>
    public enum NullSettings
    {
        Null,
        NotNull
    }
}