In a normal Latin Square, the entries in each row and column are chosen from a ``global'' set of
objects. Like a Latin square, a partial Latin square has no two rows or columns which contain the same two symbols.
However, in a partial Latin square, each cell is assigned one of its own set of possible ``local'' (and distinct)
symbols, chosen from an overall set of more than three distinct symbols, and these symbols may vary from location to location.
For example, given the possible symbols 1, 2, ..., 6 which must be arranged as
See also Dinitz Problem, Latin Square
Cipra, B. ``Quite Easily Done.'' In What's Happening in the Mathematical Sciences 2, pp. 41-46, 1994.