What is 08/15?
German slang for something very simple, poor and "not special".
History: This slang comes from the German military. The 08/15 was a standard Machine Riffle, that was first produced in 1908 and later modified.
It was the first standardized industrial product and the birth of the german DIN (=German Industrial Standard).
The soldiers dind't liked it very well, so it became a slang for something that is very common.
Windows is a 08/15 operation system.