Gets the text that is displayed in front of the number in a numbered list. If this property is an empty string, no additional text is diplayed in front of the number. Takes a callback function with one parameter as a parameter. The callback function is called with the value as parameter upon receiving the information from the server.
A function with one parameter is called with the text that is displayed in front of the number in a numbered list.
The property returns an empty string when the text selection contains multiple paragraphs with mixed settings or when the text selection does not contain a numbered list.