Before anyone gets upset here, this is the left-handed suastika, a Buddhist symbol, and the opposite of the Nazi symbol.
The outermost arms of the symbol are shown in the guidebook as being skinnier than the cross in the center. While I could indicate this with dashes on the top and bottom lines, I do not have any good way to show this on the two vertical lines. Just note that the picture shows the outer half of these squares as not being filled.