For working on R12 every Technical Consultant needs information about changes made as part of R12.
If you are upgrading from 11i to R12 and try to incorporate custom RICE then most of them fail giving an error message " Object Not Found". i.e The DB object that was earlier used in Apps 11i has been Obsoleted or it may be modified in R12.
Please find the attached document containing the changed and Obsolete Database Objects in R12.
Chaitanya Chowdary S.
List of changed or obsolete data base objects in r12 2011-03-19
List of changed or obsolete data base objects in r12