You can create crosswalks for code lists that belong to the same reference data set or different reference data sets. When you create a crosswalk, you configure a source code list and a target code list. You create one-way value mappings between code values in the source code list and code values in the target code list. Value mappings provide a way to translate the code values in the source code list to code values in the target code list. The crosswalk and the value mappings are associated with the source code list.

If code values in a pair of code lists are equivalent, you must create two crosswalks. When you create the crosswalks, use the same pair of code lists in reversed order as the source and target code lists. You must create two crosswalks because each code list can be used as a source code list and crosswalks are stored with the source code list. You cannot create multiple crosswalks for the same source and target code lists.

For example, your organization might have a Country Codes reference data set with code lists for enterprise country codes and ISO country codes. You might create the following crosswalks to map code values in the code lists:

Create a crosswalk with the Enterprise Country Codes code list as the source code list and the ISO Country Codes code list as the target code list.
Map the code value "Afghanistan" in the Enterprise Country Codes code list to the code value "AF" in the ISO Country Codes code list. The value mapping shows that the code value "Afghanistan" can be translated to the "AF" code value.
Create a crosswalk with the ISO Country Codes code list as the source code list and the Enterprise Country Codes code list as the target code list.
Map the code value "AF" in the ISO Country Codes code list to the code value "Afghanistan" in the Enterprise Country Codes code list. The value mapping shows that the code value "AF" can be translated to the "Afghanistan" code value.

After you create a crosswalk, the crosswalk is associated to the source code list as an outgoing crosswalk and to the target code list as an incoming crosswalk. Use the

Explore

panel to view code lists and the associated outgoing and incoming crosswalks. An outgoing crosswalk appears below the source code list and shows the source code values that map to the target code values. An incoming crosswalk appears below the target code list and shows the source code values that map to the target code values.

The following diagram shows a sample crosswalk: