identifier
A string used to identify the layout guide.
Declaration
var identifier: NSUserInterfaceItemIdentifier { get set }Discussion
By default, the identifier property is nil. You can assign a string to help identify this guide. This string appears as part of the guide’s description when the guide is printed to the console. You can also use the identifier to find a particular layout guide from among the guides owned by a view.
Identifiers starting with “NS” or “UI” are reserved by the system. The system may assign these identifiers to the guides it creates.