Restrictions in Unicode Programs
The adjustments you have to make and the restrictions that apply in the Unicode context have been limited to the essentials on the ABAP development side to keep the conversion effort for ABAP users to a minimum. In some cases, however, this has led to the emergence of more complex rules, for example, with regard to assignments and comparisons between incompatible structures.
Character-Type and Numeric-Type Operands
Access Using Offset and Length Specifications
Type Checks and Type Compatibility
Changes to Database Operations