Black or dark stools are a common side effect that may be the harmless result of unabsorbed iron. Whether you are taking iron supplements alone or a multivitamin with iron, you may experience this. Check with your doctor or healthcare provider to find the cause of black stools.
CCYYMMDD is just yyyyMMdd. The CC is for the two digit century which is the same as the first two digits of the year. I think people do that because people see yyyy and still type 12 instead of 2012. So today's date would be 20120717.
The files with the .dwg extension contain a database of 2D or 3D drawings that have been created within a CAD software. These files store design and meta data that describe the contents of the file. The .dwg format is considered to be the most widely-used format for CAD drawings.