public class Property : DomainObject<Guid>, IEquatable<Property>
	{
		public virtual string Name { get; set; }
		public virtual string Description { get; set; }
		public virtual PropertyTypeEnum? Type { get; set; }
.......

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">

	<class name="NVX.Tenders.Core.Domain.Property, NVX.Tenders.Core" table="Property" lazy="true" optimistic-lock="version">

		<id name="ID" column="ID">
			<generator class="guid" />
		</id>

		<property name="Name" />
		<property name="Description" />
		<property name="Type" />

	</class>

</hibernate-mapping>

	public class AuctionTypeProperty : DomainObject<Guid>, IEquatable<AuctionTypeProperty>
	{
		public virtual string DefaultValue { get; set; }
		public virtual int? OrderIndex { get; set; }

		public virtual Property Property { get; set; }
		public virtual AuctionType AuctionType { get; set; }
.............

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">

	<class name="NVX.Tenders.Core.Domain.AuctionTypeProperty, NVX.Tenders.Core" table="AuctionTypeProperty" lazy="true" optimistic-lock="version">

		<id name="ID" column="ID">
			<generator class="guid" />
		</id>

		<property name="DefaultValue" />
		<property name="OrderIndex" />

		<many-to-one name="Property" column="PropertyID" class="NVX.Tenders.Core.Domain.Property, NVX.Tenders.Core" />
		<many-to-one name="AuctionType" column="AuctionTypeID" class="NVX.Tenders.Core.Domain.AuctionType, NVX.Tenders.Core" />

	</class>

</hibernate-mapping>

	public class AuctionType : DomainObject<Guid>, IEquatable<AuctionType>
	{
		public virtual string Name { get; set; }
		public virtual string Description { get; set; }

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">

	<class name="NVX.Tenders.Core.Domain.AuctionType, NVX.Tenders.Core" table="AuctionType" lazy="true" optimistic-lock="version">

		<id name="ID" column="ID">
			<generator class="guid" />
		</id>

		<property name="Name" />
		<property name="Description" />

	</class>

</hibernate-mapping>