IPC-SM-782 releasedin 1987 and was active for 18 years, had Level B as the default Zero ComponentOrientation . PCB Libraries, Inc. created the first Land Pattern Calculator in2001 using Level B Zero Component Orientation for both IPC-SM-782 and the newIPC-7351 standards.

Then in 2005 theIPC-7351 committee had one meeting at IPC APEX in Anaheim, CA that changed theZero Component Orientation to Level A. So PCB Libraries updated LP Wizard tomatch the new Level A Zero Component Orientation.

Then in 2007 IEC inEurope released a new Zero Component Orientation standard IEC 61188-7 withLevel B as the world standard. LP Wizard stayed with Level A Zero ComponentOrientation because of IPC-7351.

The new LibraryExpert now defaults to Level B Zero Component Orientation because IPC-7351Cwill introduce it to be compatible with both IPC-SM-782 and IEC 61188-7. However,Library Expert users can change the Zero Component Orientation to whateverOrientation they want in User Preferences.