When you install or activate your license of an Autodesk application, you need to enter the "Product key" and the "Serial number". Both these values can be found on the back side of the package of your installation media, or (with electronic fulfillment) on your subscription center (web; after you log in, or in the e-mail you have received).
The Product Key differentiates licenses of the individual applications, which may be delivered on a single installation media - e.g. Inventor Suite and Inventor Professional, or differentiates products of the same family - e.g. Revit. The Product Key is language-independent.
Examples of some product keys in the 2011 and 2012 family:
- 001C1 - AutoCAD 2011
- 001D1 - AutoCAD 2012
- 527C1 - Inventor Suite 2011
- 462C1 - Inventor Professional 2011
- 240C1 - Revit Architecture 2011
- 241C1 - AutoCAD Revit Architecture Suite 2011
- 595C1 - AutoCAD Revit Architecture Visualization Suite 2011
- 255C1 - Revit Structure 2011
- 256C1 - AutoCAD Revit Structure Suite 2011
- 297C1 - Revit MEP 2011
- 257C1 - AutoCAD Revit MEP Suite 2011
You can also get the Product key from the MID01.TXT file on the installation media. The code is in the first 5 characters of the Part number.
And a little trick at the end. If you need a specific product key for an Autodesk application, lookup this application in the CAD Studio CAD eShop. The first 5 characters of the specific part number is the product key.