  The principal permanent rank characteristic sequence is a binary sequence
$r_0 r_1 \ldots r_n$ where $r_k = 1$ if there exists a principal square
submatrix of size $k$ with nonzero permanent and $r_k = 0$ otherwise, and $r_0
= 1$ if there is a zero diagonal entry.
  A characterization is provided for all principal permanent rank sequences
obtainable by the family of nonnegative matrices as well as the family of
nonnegative symmetric matrices. Constructions for all realizable sequences are
provided.
  Results for skew-symmetric matrices are also included.
