As part of the semantic integration paradigm, it is important to note that all transformation code and business rules refer to the data fields using their definition names and not the names used by their respective resources. The expressor illustrator scripting window, coding aids, and schema viewers show only the definition names and access the definition specific business rules. Consequently, all data manipulation within the expressor engine uses these semantically rationalized definition names and their corresponding expressor data types. Only when data is read into, or emitted from, the expressor integration does the engine use the resource specific field names and types.