This standard uses ModellingRulethat are OptionalPlaceholderand MandatoryPlaceholderto define instance declarations, and defines a rule that the BrowseName of instance declarations having an OptionalPlaceholderor MandatoryPlaceholder ModellingRulebe enclosed in angle brackets (<>). Originally, this rule is defined in OPC 10000-3as a recommendation. This naming rule is also used in the description of a table. The BrowseNameof a Node that has OptionalPlaceholderor MandatoryPlaceholder ModellingRuleare described with angle brackets, which denotes that the name is not fixed. For example BrowseNameof Propertyis described as <PropertyName> in graphical notation and tables results in a Propertythat can have any name.