19=network license NLM
2a=standalone licence SLM
Using the registry hack with AutoCAD 2009 and later the cascading licensing service doesn’t install, so cascading will not work when converted from SLM to NLM. If you install network version and convert to SLM then PLU doesn’t install and user will not be able to transfer his license.
See also Change AutoCAD network to standalone to network on how to get the cascading licensing service installed.
UPDATE: For newer versions take a look at How to change AutoCAD from network license to standalone, Change AutoCAD 2013 from Network license to Standalone and Change AutoCAD 2014 from Network license to Standalone