The ESRI Location Fields list determines the columns that are treated by ArcGIS Mapping as geographic. The key values in this list are in the Aliases column. If a list within the same site collection as the ESRI Location Fields list contains a column with a name matching any one of the comma-delimited values in the Aliases column, then ArcGIS Mapping will treat the list as geographic. This means that the list will appear as a data source in the ArcGIS Map Web Part and as an item in the List column of the ESRI List Location Properties list.

If you want ArcGIS Mapping to recognize additional field names as geographic, simply edit the Aliases column of one of the items in this list and add the additional names to the list of comma-delimited values.