Dot Wordsworth in the Speccie:
'Hospitals named after sandwiches kill five,' ran a headline in the Times in June. When it was tweeted by the journalist Adam Macqueen, people pointed out that there really is a Mayo Clinic (in Minnesota), though egg or tuna is not specified, and there had been a BLT group of hospitals (Barts and the London Trust).
Such artlessly ambiguous headlines have, since 2009, been called crash blossoms, at the suggestion of an editor called Dan Bloom, suitably enough. The name derives from a headline in Japan Today: 'Violinist Linked to JAL Crash Blossoms'. The article below it concerned the success of Diana Yukawa, whose father had died in a Japan Airlines crash.
Ambiguity thrives because English often uses the same words either as nouns or verbs, and in a headline it may be hard to tell which. The classic example, from the first world war, or from nowhere, is 'French push bottles up German rear'. Ben Zimmer, writing in the New York Times a few years ago, chose as one of his favourites: 'McDonald's Fries the Holy Grail for Potato Farmers'. (American papers capitalise the main words in headlines.)
Such headlines do accidentally what crossword clues do on purpose: lead readers astray. Thus 'Bar of soap (3,6,6)' had the solution 'The Rovers Return', the pub in Coronation Street. A one-word clue 'Number (12)' demanded the solution 'Anaesthetist'.