> [...] a screw on the rail had dragged through the QR code in a horizontal line - not through the timing section, but enough to make it unreadable. Given that

> [...] a screw on the rail had dragged through the QR code in a horizontal line - not through the timing section, but enough to make it unreadable. Given that two timing patterns are perpendicular to each other, how is that possible? Did the line come from the rightmost boundary and stop before the vertical timing pattern? Then there should be no real difficulty in reading that and it might well be a decoder problem.