diff --git a/rendercv/data_models.py b/rendercv/data_models.py
index 84e64a1..9872937 100644
--- a/rendercv/data_models.py
+++ b/rendercv/data_models.py
@@ -1347,6 +1347,8 @@ def generate_json_schema() -> dict[str, Any]:
         dict: The JSON schema of RenderCV.
     """
 
+    # def loop_through_pro
+
     class RenderCVSchemaGenerator(pydantic.json_schema.GenerateJsonSchema):
         def generate(self, schema, mode="validation"):  # type: ignore
             json_schema = super().generate(schema, mode=mode)
@@ -1361,7 +1363,7 @@ def generate_json_schema() -> dict[str, Any]:
 
             # Loop through $defs and remove docstring descriptions and fix optional
             # fields
-            for _, value in json_schema["$defs"].items():
+            for object_name, value in json_schema["$defs"].items():
                 # Don't allow additional properties
                 value["additionalProperties"] = False
 
@@ -1372,14 +1374,22 @@ def generate_json_schema() -> dict[str, Any]:
                 # don't want to provide them.
                 null_type_dict = {}
                 null_type_dict["type"] = "null"
-                for field in value["properties"].values():
+                for field_name, field in value["properties"].items():
                     if "anyOf" in field:
                         if (
                             len(field["anyOf"]) == 2
                             and null_type_dict in field["anyOf"]
                         ):
-                            field["allOf"] = [field["anyOf"][0]]
+                            field["oneOf"] = [field["anyOf"][0]]
                             del field["anyOf"]
+
+                            # for sections field of CurriculumVitae:
+                            if "additionalProperties" in field["oneOf"][0]:
+                                field["oneOf"][0]["additionalProperties"]["oneOf"] = (
+                                    field["oneOf"][0]["additionalProperties"]["anyOf"]
+                                )
+                                del field["oneOf"][0]["additionalProperties"]["anyOf"]
+
                         else:
                             field["oneOf"] = field["anyOf"]
                             del field["anyOf"]
diff --git a/schema.json b/schema.json
index 8853014..4a28b82 100644
--- a/schema.json
+++ b/schema.json
@@ -154,7 +154,7 @@
           "default": null,
           "description": "The name of the person.",
           "title": "Name",
-          "allOf": [
+          "oneOf": [
             {
               "type": "string"
             }
@@ -164,7 +164,7 @@
           "default": null,
           "description": "The label of the person.",
           "title": "Label",
-          "allOf": [
+          "oneOf": [
             {
               "type": "string"
             }
@@ -174,7 +174,7 @@
           "default": null,
           "description": "The location of the person.",
           "title": "Location",
-          "allOf": [
+          "oneOf": [
             {
               "type": "string"
             }
@@ -184,7 +184,7 @@
           "default": null,
           "description": "The email of the person.",
           "title": "Email",
-          "allOf": [
+          "oneOf": [
             {
               "format": "email",
               "type": "string"
@@ -195,7 +195,7 @@
           "default": null,
           "description": "The phone number of the person.",
           "title": "Phone",
-          "allOf": [
+          "oneOf": [
             {
               "format": "phone",
               "maxLength": 64,
@@ -208,7 +208,7 @@
           "default": null,
           "description": "The website of the person.",
           "title": "Website",
-          "allOf": [
+          "oneOf": [
             {
               "format": "uri",
               "maxLength": 2083,
@@ -221,7 +221,7 @@
           "default": null,
           "description": "The social networks of the person.",
           "title": "Social Networks",
-          "allOf": [
+          "oneOf": [
             {
               "items": {
                 "$ref": "#/$defs/SocialNetwork"
@@ -234,10 +234,10 @@
           "default": null,
           "description": "The sections of the CV.",
           "title": "Sections",
-          "allOf": [
+          "oneOf": [
             {
               "additionalProperties": {
-                "anyOf": [
+                "oneOf": [
                   {
                     "items": {
                       "$ref": "#/$defs/OneLineEntry"
@@ -314,7 +314,7 @@
             "MS"
           ],
           "title": "Degree",
-          "allOf": [
+          "oneOf": [
             {
               "type": "string"
             }
@@ -327,7 +327,7 @@
             "Istanbul, T\u00fcrkiye"
           ],
           "title": "Location",
-          "allOf": [
+          "oneOf": [
             {
               "type": "string"
             }
@@ -405,7 +405,7 @@
             "Did that."
           ],
           "title": "Highlights",
-          "allOf": [
+          "oneOf": [
             {
               "items": {
                 "type": "string"
@@ -614,7 +614,7 @@
             "Istanbul, T\u00fcrkiye"
           ],
           "title": "Location",
-          "allOf": [
+          "oneOf": [
             {
               "type": "string"
             }
@@ -692,7 +692,7 @@
             "Did that."
           ],
           "title": "Highlights",
-          "allOf": [
+          "oneOf": [
             {
               "items": {
                 "type": "string"
@@ -1078,7 +1078,7 @@
             "Istanbul, T\u00fcrkiye"
           ],
           "title": "Location",
-          "allOf": [
+          "oneOf": [
             {
               "type": "string"
             }
@@ -1156,7 +1156,7 @@
             "Did that."
           ],
           "title": "Highlights",
-          "allOf": [
+          "oneOf": [
             {
               "items": {
                 "type": "string"
@@ -1254,7 +1254,7 @@
             "10.48550/arXiv.2310.03138"
           ],
           "title": "DOI",
-          "allOf": [
+          "oneOf": [
             {
               "type": "string"
             }
@@ -1279,7 +1279,7 @@
           "default": null,
           "description": "The journal or the conference name.",
           "title": "Journal",
-          "allOf": [
+          "oneOf": [
             {
               "type": "string"
             }