diff --git a/RETRIEX_PATCH_21_LANGUAGE_CLEANUP_PROFILES_README.md b/RETRIEX_PATCH_21_LANGUAGE_CLEANUP_PROFILES_README.md
new file mode 100644
index 0000000..6bca05d
--- /dev/null
+++ b/RETRIEX_PATCH_21_LANGUAGE_CLEANUP_PROFILES_README.md
@@ -0,0 +1,36 @@
+# RetrieX Patch 21 - Language Cleanup Profiles groundwork
+
+## Goal
+
+Prepare RetrieX 1.5.3 for simpler, centralized language cleanup without changing runtime behavior yet.
+
+## Changes
+
+- Extends `config/retriex/language.yaml` additively.
+- Keeps legacy `retriex.stopwords.config.words` unchanged.
+- Adds central groups for protected terms, German core stopwords, conversation noise, user instruction phrases, presentation/meta terms, and cleanup profiles.
+- Introduces initial profiles: `commerce_query`, `rag_evidence`, `shop_context_fallback`.
+
+## Non-goals
+
+- No external stopword library.
+- No Commerce/Agent runtime wiring yet.
+- No removal of existing lists in `commerce.yaml`, `agent.yaml`, or `retrieval.yaml`.
+- No domain-specific special cases.
+
+## Install
+
+Copy the files from this patch over the current RetrieX root.
+
+```bash
+unzip retriex-p21-language-cleanup-profiles-patch-only.zip -d /path/to/retriex
+cd /path/to/retriex
+bin/console mto:agent:config:validate
+bin/console mto:agent:regression:test
+bin/console mto:agent:config:audit-source --details
+bin/console mto:agent:config:audit-patterns --details
+```
+
+## Expected result
+
+All checks should remain green. This patch should not change answers yet.
diff --git a/config/retriex/language.yaml b/config/retriex/language.yaml
index 42081c3..75a937b 100644
--- a/config/retriex/language.yaml
+++ b/config/retriex/language.yaml
@@ -50,3 +50,106 @@ parameters:
       - würde
       - würdest
       - würden
+
+    # Central language cleanup structure for RetrieX 1.5.3+.
+    # Legacy key `words` above remains the runtime-compatible default list.
+    # New cleanup profiles are introduced additively and are not yet wired into
+    # Commerce/Agent runtime logic in this patch.
+    protected_terms:
+      - nicht
+      - kein
+      - keine
+      - testomat
+      - indikator
+      - indikatortyp
+      - ph
+      - rx
+      - th
+      - tc
+      - '0,02'
+
+    stopword_groups:
+      de_core:
+        - der
+        - die
+        - das
+        - den
+        - dem
+        - des
+        - ein
+        - eine
+        - einer
+        - eines
+        - und
+        - oder
+        - mit
+        - für
+        - fuer
+        - ist
+        - sind
+        - kann
+        - können
+        - koennen
+
+      conversation:
+        - bitte
+        - mal
+        - gerne
+        - gern
+        - auch
+        - noch
+        - nochmal
+        - dazu
+        - davon
+        - also
+        - danke
+
+    phrase_groups:
+      user_instruction:
+        - ich suche
+        - suche nach
+        - zeige mir
+        - zeig mir
+        - gib mir
+        - gebe mir
+        - nenne mir
+        - habt ihr
+        - gibt es
+        - suche im shop
+
+    meta_term_groups:
+      presentation:
+        - tabelle
+        - tabellarisch
+        - liste
+        - übersicht
+        - uebersicht
+        - auflistung
+
+    cleanup_profiles:
+      commerce_query:
+        stopword_groups:
+          - de_core
+          - conversation
+        phrase_groups:
+          - user_instruction
+        protected_term_groups:
+          - protected_terms
+
+      rag_evidence:
+        stopword_groups:
+          - de_core
+          - conversation
+        protected_term_groups:
+          - protected_terms
+
+      shop_context_fallback:
+        stopword_groups:
+          - de_core
+          - conversation
+        phrase_groups:
+          - user_instruction
+        meta_term_groups:
+          - presentation
+        protected_term_groups:
+          - protected_terms