Masthead used to be the term for the heading at the top of the front page of the newspaper. In this context, Masthead is the generic name for the publisher. media owners like News Limited or Nine own multiple newspapers. In articles they use the term "this masthead" rather than "The Telegraph" or "Sydney Morning Herald" so that they can copy/paste the entire article in multiple papers, so by saying "this masthead" a News Ltd article can be printed in The Daily Telegraph, The Advertiser, The Australian, herald Sun Courier Mail etc and read normally without editing.