You can create dictionaries with any data that is useful to the data project that you work on. The dictionary does not evaluate the data that you enter, and the values in each column do not need to be objectively correct or incorrect.
Consider the following scenarios:
•The dictionary might include alternative versions of the same data, such as Massachusetts and MA.
•The dictionary might include values that relates to each other in a way that is relevant to your business, such as Massachusetts and Boston.
•The dictionary might include correct and incorrect spellings of the same data, such as Massachusetts and Massachusets.
Each row in a dictionary can have a different number of values. For example, the number of telephone area codes in each state of the United States varies from state to state. If you create a dictionary that matches the area codes to their respective states, the rows for each state will have different numbers of values.
The following table shows a fragment of a dictionary of United States telephone area codes: