linear operator; zero-term rank; $P,Q,B$-operator
Zero-term rank of a matrix is the minimum number of lines (rows or columns) needed to cover all the zero entries of the given matrix. We characterize the linear operators that preserve zero-term rank of the $m \times n$ real matrices. We also obtain combinatorial equivalent condition for the zero-term rank of a real matrix.
 C. R. Johnson and J. S. Maybee: Vanishing minor conditions for inverse zero patterns
. Linear Algebra Appl. 178 (1993), 1–15. MR 1197498