diff --git a/specification/resources/apps/models/app_ingress_spec_rule_string_match_exact.yml b/specification/resources/apps/models/app_ingress_spec_rule_string_match_exact.yml
index 083ff070..355eb3d4 100644
--- a/specification/resources/apps/models/app_ingress_spec_rule_string_match_exact.yml
+++ b/specification/resources/apps/models/app_ingress_spec_rule_string_match_exact.yml
@@ -2,8 +2,12 @@ type: object
 properties:
   exact:
     type: string
+    nullable: true
     maxLength: 256
     example: "example.com"
+    description: >-
+      Exact string match. An empty string is a valid value and will be
+      serialized explicitly rather than being omitted from the payload.
 description: The authority to match on.
 required:
   - exact
diff --git a/specification/resources/apps/models/app_ingress_spec_rule_string_match_prefix.yml b/specification/resources/apps/models/app_ingress_spec_rule_string_match_prefix.yml
index 3158e91c..4c6d8d92 100644
--- a/specification/resources/apps/models/app_ingress_spec_rule_string_match_prefix.yml
+++ b/specification/resources/apps/models/app_ingress_spec_rule_string_match_prefix.yml
@@ -2,6 +2,7 @@ type: object
 properties:
   prefix:
     type: string
+    nullable: true
     description: Prefix-based match. For example, `/api` will match `/api`, `/api/`, and any nested paths such as `/api/v1/endpoint`.
     maxLength: 256
     example: /api
diff --git a/specification/resources/apps/models/apps_string_match.yml b/specification/resources/apps/models/apps_string_match.yml
index dd06a473..a695ad31 100755
--- a/specification/resources/apps/models/apps_string_match.yml
+++ b/specification/resources/apps/models/apps_string_match.yml
@@ -2,18 +2,19 @@ type: object
 properties:
   exact:
     type: string
+    nullable: true
     description: Exact string match. Only 1 of `exact`, `prefix`, or
-      `regex` must be set.
+      `regex` must be set. An empty string is a valid value and will be
+      serialized explicitly rather than being omitted from the payload.
     maxLength: 256
-    minLength: 1
     example: https://www.example.com
 
   prefix:
     type: string
+    nullable: true
     description: Prefix-based match. Only 1 of `exact`, `prefix`, or
       `regex` must be set.
     maxLength: 256
-    minLength: 1
     example: https://www.example.com
     deprecated: true