In order to support ULC Smalltalk applications written before Release 3.0, the ULC application can run in Compatibility mode. The application runs in compatibility mode when it pre-requisites the application UlcNlsCompatibilityApp. This mode, the Pre-R3.0 NLS Compatibility Mode, allows existing applications to work without any change. When using this mode, any strings coming out of the new MPR files are converted to Strings and any string data returning from the client is placed into String. For information on migrating the MPR files, see Migrating MPR files.