linux-packaging-mono/mcs/class/referencesource/System.ComponentModel.DataAnnotations/DataAnnotations/Schema/NotMappedAttribute.cs

using System.Diagnostics.CodeAnalysis;

namespace System.ComponentModel.DataAnnotations.Schema {
    /// <summary>
    /// Denotes that a property or class should be excluded from database mapping.
    /// </summary>
    [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Class, AllowMultiple = false)]
    [SuppressMessage("Microsoft.Performance", "CA1813:AvoidUnsealedAttributes", Justification = "We want users to be able to extend this class")]
    public class NotMappedAttribute : Attribute {
    }
}