According to the ISO specification the No symbol's cross should be the other way( ⃠ ) —http://en.wikipedia.org/wiki/No_symbol

The no symbol (also prohibition sign, no sign, circle-backslash symbol, nay, or universal no) is a circle with a diagonal line through it (running from top left to bottom right), surrounding a pictogram used to indicate something is not permitted. The no symbol is generally colored red, but is sometimes another color, typically black.