Reserved words are pieces of SQL syntax that have special meaning when used as part of a command.
Transact-SQL does not allow words that are part of command syntax to be used as identifiers unless they are enclosed in quotation marks. If you are upgrading SAP ASE, you see errors when you run queries, stored procedures, or applications that use these identifiers in your user databases.
If you change an object name, also change applications and stored procedures that refer to that object. Conflicts between object names do not prevent the upgrade process from completing. However, applications that refer to conflicting object names may not work after the upgrade. Rename all objects that use reserved words.
As part of the preupgrade process, you can have sqlupgrade, sqlupgraderes, or preupgrade perform a reserved-word check for you. See the Reference Manual: Building Blocks for a complete list of reserved words.