diff --git a/models.yml b/models.yml
index 4a3df669..2911ebb2 100644
--- a/models.yml
+++ b/models.yml
@@ -57,6 +57,31 @@
 #   The field `restriction_mode` is required for every field. It puts the field into a
 #   restriction group. See https://github.com/OpenSlides/OpenSlides/wiki/Restrictions-Overview
 
+_meta:  # meta field to hold repeatedly used values
+  languages: &languages
+    - en
+    - de
+    - it
+    - es
+    - ru
+    - cs
+  ballot_paper_selection: &ballot_paper_selection
+    - NUMBER_OF_DELEGATES
+    - NUMBER_OF_ALL_PARTICIPANTS
+    - CUSTOM_NUMBER
+  poll_backends: &poll_backends
+    - long
+    - fast
+  onehundred_percent_bases: &onehundred_percent_bases
+    - "Y"
+    - "YN"
+    - "YNA"
+    - "N"
+    - "valid"
+    - "cast"
+    - "entitled"
+    - "disabled"
+
 organization:
   id:
     type: number
@@ -112,13 +137,7 @@ organization:
   default_language:
     type: string
     restriction_mode: A
-    enum:
-      - en
-      - de
-      - it
-      - es
-      - ru
-      - cs
+    enum: *languages
     required: true
 
   # Saml settings
@@ -755,13 +774,7 @@ meeting:
   language:
     type: string
     restriction_mode: A
-    enum:
-      - en
-      - de
-      - it
-      - es
-      - ru
-      - cs
+    enum: *languages
     required: true
 
   # Configuration (only for the server owner)
@@ -1194,10 +1207,7 @@ meeting:
   # Motion poll
   motion_poll_ballot_paper_selection:
     type: string
-    enum:
-      - NUMBER_OF_DELEGATES
-      - NUMBER_OF_ALL_PARTICIPANTS
-      - CUSTOM_NUMBER
+    enum: *ballot_paper_selection
     default: CUSTOM_NUMBER
     restriction_mode: B
   motion_poll_ballot_paper_number:
@@ -1210,6 +1220,7 @@ meeting:
     restriction_mode: B
   motion_poll_default_onehundred_percent_base:
     type: string
+    enum: *onehundred_percent_bases
     default: YNA
     restriction_mode: B
   motion_poll_default_group_ids:
@@ -1218,10 +1229,8 @@ meeting:
     restriction_mode: B
   motion_poll_default_backend:
     type: string
+    enum: *poll_backends
     default: fast
-    enum:
-      - long
-      - fast
     restriction_mode: B
 
   # poll list election
@@ -1321,10 +1330,7 @@ meeting:
   # Assignment polls
   assignment_poll_ballot_paper_selection:
     type: string
-    enum:
-      - NUMBER_OF_DELEGATES
-      - NUMBER_OF_ALL_PARTICIPANTS
-      - CUSTOM_NUMBER
+    enum: *ballot_paper_selection
     default: CUSTOM_NUMBER
     restriction_mode: B
   assignment_poll_ballot_paper_number:
@@ -1353,6 +1359,7 @@ meeting:
     restriction_mode: B
   assignment_poll_default_onehundred_percent_base:
     type: string
+    enum: *onehundred_percent_bases
     default: valid
     restriction_mode: B
   assignment_poll_default_group_ids:
@@ -1361,19 +1368,14 @@ meeting:
     restriction_mode: B
   assignment_poll_default_backend:
     type: string
+    enum: *poll_backends
     default: fast
-    enum:
-      - long
-      - fast
     restriction_mode: B
 
   # Polls
   poll_ballot_paper_selection:
     type: string
-    enum:
-      - NUMBER_OF_DELEGATES
-      - NUMBER_OF_ALL_PARTICIPANTS
-      - CUSTOM_NUMBER
+    enum: *ballot_paper_selection
     restriction_mode: B
   poll_ballot_paper_number:
     type: number
@@ -1390,6 +1392,7 @@ meeting:
     restriction_mode: B
   poll_default_onehundred_percent_base:
     type: string
+    enum: *onehundred_percent_bases
     default: YNA
     restriction_mode: B
   poll_default_group_ids:
@@ -1398,10 +1401,8 @@ meeting:
     restriction_mode: B
   poll_default_backend:
     type: string
+    enum: *poll_backends
     default: fast
-    enum:
-      - long
-      - fast
     restriction_mode: B
   poll_couple_countdown:
     type: boolean
@@ -2931,10 +2932,8 @@ poll:
   backend:
     type: string
     required: True
+    enum: *poll_backends
     default: fast
-    enum:
-      - long
-      - fast
     restriction_mode: A
   is_pseudoanonymized:
     type: boolean
@@ -2987,15 +2986,7 @@ poll:
   onehundred_percent_base:
     type: string
     required: true
-    enum:
-      - "Y"
-      - "YN"
-      - "YNA"
-      - "N"
-      - "valid"
-      - "cast"
-      - "entitled"
-      - "disabled"
+    enum: *onehundred_percent_bases
     default: disabled
     restriction_mode: A
   votesvalid:
diff --git a/models_validator/validate.py b/models_validator/validate.py
index f7bc6685..690d73c5 100644
--- a/models_validator/validate.py
+++ b/models_validator/validate.py
@@ -72,8 +72,10 @@ def run_check(self) -> None:
             raise CheckException("\n".join(errors))
 
     def _run_checks(self) -> None:
-        for collection in self.models.keys():
-            if not COLLECTION_REGEX.match(collection):
+        for collection in list(self.models.keys()):
+            if collection.startswith("_"):
+                self.models.pop(collection)
+            elif not COLLECTION_REGEX.match(collection):
                 self.errors.append(f"Collection '{collection}' is not valid.")
         if self.errors:
             return