These are the words that identify a story. The slug is not a headline. It is the name of the story and should be two words maximum where possible.
If a slug is allocated it is important all reporters use the exact slug (story title) for their intro, scripts, graphics, rundown, online content etc.. Also, no two item slugs should have the same word in them. There is potential for disaster if one story is slugged “fire deaths” and the other “fire sale”.
