The rule implemented by the function normally applies to words representing locations. In most cases, the function provides an output that is associated with the input location. For example, "UAE" maps to "Oman", "Bulgaria" maps to "Romania", and "Spain" maps to "France". However, there are some inputs for which the function does not provide a defined output, such as "Dallas", "Lena", "Wolf", and "Ankara". In these cases, the mapping is either undefined or not within the scope of the defined rule.