Sentence:  When the wedding started I found a spot near Windsor Castle's entrance, where I could watch the ceremony on a big screen. People who line the roads at weddings are, by definition, the most die-hard royalists, and all the usual figures were out in force: the men bellowing and ringing bells in the hope of convincing a passing American TV crew they are an actual town crier; the men in suits made of <WSD>Union Jacks</WSD>. 
Meaning of the word marked with <WSD> tags:  The flag of the United Kingdom, consisting of the flags of England (St. George's Cross), Scotland (St. Andrew's Cross), and Ireland (St. Patrick's Cross) now only used in Northern Ireland combined.