When Will Shortz was gathering material for his recently-published book, World Class Championship Crosswords (Simon & Schuster, 1982), he visited me to consult some of my historical crossword competition material. We soon got into a spirited discussion about inadvertent ambiguity in British-style crossword puzzles: I maintained that the plethora of "outs" (black squares) in British diagrams allowed crossword fans sometimes to write different correct answers into the same word-path, whereas Will Shortz insisted that the typical British clue would not allow such a possibility.
"Those Cryptic British Crosswords,"
Word Ways: Vol. 16
, Article 14.
Available at: https://digitalcommons.butler.edu/wordways/vol16/iss2/14