The whole grid is an N x N square of cells where N is an odd number.
The pattern of black and white cells has 180-degree rotational symmetry.
Answers ... ... are all at least 3 letters long;
... are all different.
White cells ... ... are all "checked"
(part of both an Across answer and a Down answer).
... are orthogonally contiguous
(no islands when considering shared edges);