To construct a Latin word square, make a word square out of words with non-repeated letters and rank the letters to each word by their alphabetic position (for example, ALICE-15423). If the ranking for horizontal words remains valid for the vertical words, then the square is Latin. The concept of Latin word squares was proposed by Dave Silverman in the August 1972 Kickshaws; in February 1973, Mary Younquist and Murray Pearce exhibited sever 4-by-4 Latin word squares, and Mary exhibited a 5-by-5 example with three invented but plausible "words."
"5-By-5 Latin Word Squares,"
Word Ways: Vol. 23
, Article 10.
Available at: http://digitalcommons.butler.edu/wordways/vol23/iss4/10