When text is used in a UaNodeSet, for example in the Description Attribute, this text will show up in the AddressSpace of OPC UA Servers, where in each Server the NamespaceIndex very likely will be different than defined in the Companion Specification.
Therefore, it is recommended to omit the NamespaceIndex in those places and just use the Name-part of the BrowseName. For example, “The unit is defined in the EngineeringUnits property.” In almost all cases, there will not be two BrowseNames in the context of the Description, where the same Name is used twice with different Namespaces. In very rare cases, where it can be foreseen that this will or may happen, the text should explicitly reference the Namespace, not the NamespaceIndex. For example: “The unit is defined in the EngineeringUnits property specified by ‘http://opcfoundation.org/UA/’”.