Mold vs Mould

same word as 

in the US :  only MOLD (moldy, molded)
the bread is dry and moldy
the mold on damp walls
the cookies were formed by a mold.

Outside the US (everybody else) only MOULD
the bread is mouldy
the mould on damp walls
the bread was baked in a mould.

and Canada, again, in the middle
MOULD is preferred but some publications use the american "mold"

Well, that clears it up