When you run AXBUILD with AX2012 R3 you might notice there are some classes that throws warnings, even though you know they are not customized. Why is that?
Here is an example running CU10 and the following classes are flagged for investigation.
*** Bad element: \\Classes\AssetBookBonusMethod_IN
*** Bad element: \\Classes\PCImportModel
*** Bad element: \\Classes\VendInvoicePostBatchCleanup
The reason these classes throws warnings is the SysObsoleteAttribute where you can force compiler warnings with the second parameter.
There are system classes marked as obsolete and while you could argue they should be removed, there may be dependencies to them - out there somewhere -still.