Flash MX 2004.
Library.getItemProperty(property)
stringFor a list of values that you can use as a property parameter, see the Property summary table for the Item object, along with property summaries for its subclasses.
A string value for the property.
stringMethod; Gets the property for the selected item.
The following example shows a dialog box that contains the Linkage Identifier value for the symbol when referencing it using ActionScript or for run-time sharing:
alert(fl.getDocumentDOM().library.getItemProperty("linkageIdentifier"));