diff --git a/dbt/models/iasworld/schema.yml b/dbt/models/iasworld/schema.yml
index 62f8d290e..a4e337bc9 100644
--- a/dbt/models/iasworld/schema.yml
+++ b/dbt/models/iasworld/schema.yml
@@ -143,6 +143,19 @@ sources:
               combination_of_columns:
                 - parid
                 - taxyr
+          - column_is_subset_of_external_column:
+              name: pardat_nbhd_matches_spatial_town_nbhd
+              column: nbhd
+              external_model: spatial.neighborhood
+              external_column: town_nbhd
+              additional_select_columns:
+                - parid
+                - taxyr
+              config:
+                # Codes ending in 999 are dummy codes used for some purpose,
+                # although we do not yet know what it is
+                where: (taxyr between '2010' and '2021') and (nbhd not like '%999')
+                error_if: ">1992"
       - name: permit
         freshness:
           filter: date_format(date_parse(permdt, '%Y-%m-%d %H:%i:%s.0'), '%Y') >= date_format(current_date - interval '1' year, '%Y')
diff --git a/dbt/tests/generic/test_column_is_subset_of_external_column.sql b/dbt/tests/generic/test_column_is_subset_of_external_column.sql
new file mode 100644
index 000000000..a6ab00062
--- /dev/null
+++ b/dbt/tests/generic/test_column_is_subset_of_external_column.sql
@@ -0,0 +1,28 @@
+-- Test that a given column is a subset of a column in an external relation.
+--
+-- Returns rows where `column` has no matches in the external relation, with
+-- additional return columns drawn from the base relation as specified by
+-- `additional_select_columns`.
+{% test column_is_subset_of_external_column(
+    model,
+    column,
+    external_model,
+    external_column,
+    additional_select_columns=[]
+) %}
+
+    {%- set additional_select_columns_csv = additional_select_columns | join(", ") %}
+    {%- set columns_csv = additional_select_columns_csv ~ ", " ~ column %}
+
+    with
+        distinct_external_values as (
+            select distinct ({{ external_column }}) as external_column
+            from {{ external_model }}
+        )
+    select {{ columns_csv }}
+    from {{ model }}
+    left join
+        distinct_external_values dist_ext on {{ column }} = dist_ext.external_column
+    where dist_ext.external_column is null
+
+{% endtest %}