I am concerned how the AnalogItemType and related EUInformation are designed, with respect to information duplicity and memory consumption.
If undestanding it properly, any instance of AnalogItemType supporting EUInformation will have a new separate instance of EUInformation, which contans its own copy of all fields m_namespaceUri, m_unitId, m_displayName, m_description. For any new created AnalogItemType , completre new EUInformation is created ( code fragment below ). Imagine an array of 100x100 AnalogItemType values.
Is not more feasible some some alternative design, perhaps with AnalogItemType just containing a reference to EUInformation, single per server ( or AnalogItemType containg just Id of a unit, and EUInformation itself available in a global map Id -> EUInformation) ?

// ------- DaItemState.cs
Code:

/// <summary>
/// Initializes the node from the element.
/// </summary>
public void Initialize(ISystemContext context, DaElement element, ushort namespaceIndex)
{
...
// set the TypeDefinition based on the ElementType.
switch (element.ElementType)
{
...
case DaElementType.AnalogItem:
{
...
// check if EngineeringUnits is supported.
if (element.EngineeringUnits != null)
{
...
property.Value = new EUInformation(element.EngineeringUnits, namespaceUri);
}
break;
}
...

// ------- Opc.Ua.Types.xsd
Code:

<xs:complexType name="EUInformation">
<xs:sequence>
<xs:element name="NamespaceUri" type="xs:string" minOccurs="0" nillable="true" />
<xs:element name="UnitId" type="xs:int" minOccurs="0" />
<xs:element name="DisplayName" type="ua:LocalizedText" minOccurs="0" nillable="true" />
<xs:element name="Description" type="ua:LocalizedText" minOccurs="0" nillable="true" />
</xs:sequence>
</xs:complexType>

To Petr Kodet:
This is a false assumption. Servers may share any property across all instances where it applies to.

If a server permits writing to such shared properties it has to differentiate two use cases:
(1) The change shall affect all instances or
(2) The change shall only affect a single instance. In this latter case the server has to maintain separate NodeIds for each instance and has to initialise a new property instance when such a Write is performed. In this case the additional memory consumption is necessary

Fixed in doc 1.02.16

Added optional property to node class Variable.
Made forward reference for data type and details of definition to part 8.

Rreviewed and agreed in telecon.