diff --git a/klausur-service/backend/cv_ocr_engines.py b/klausur-service/backend/cv_ocr_engines.py
index ba2d1e1..4bed09b 100644
--- a/klausur-service/backend/cv_ocr_engines.py
+++ b/klausur-service/backend/cv_ocr_engines.py
@@ -1881,6 +1881,11 @@ def _is_noise_tail_token(token: str) -> bool:
     if t.endswith(']'):
         return False
 
+    # Keep meaningful punctuation tokens used in textbooks
+    # = (definition marker), (= (definition opener), ; (separator)
+    if t in ('=', '(=', '=)', ';', ':', '-', '–', '—', '/', '+', '&'):
+        return False
+
     # Pure non-alpha → noise ("3", ")", "|")
     alpha_chars = _RE_ALPHA.findall(t)
     if not alpha_chars:
diff --git a/klausur-service/backend/grid_build_core.py b/klausur-service/backend/grid_build_core.py
index 037c578..954aef8 100644
--- a/klausur-service/backend/grid_build_core.py
+++ b/klausur-service/backend/grid_build_core.py
@@ -1575,7 +1575,10 @@ async def _build_grid_core(
             if not core:
                 is_artifact = True
             elif _PURE_JUNK_RE.match(core):
-                is_artifact = True
+                # Keep meaningful punctuation tokens used in textbooks
+                # = (definition), (= (definition), ; : - are valid content
+                if core.strip() not in ('=', '(=', '=)', ';', ':', '-', '–', '—'):
+                    is_artifact = True
             elif len(core) <= 2 and core.lower() not in _COMMON_SHORT_WORDS and not core.isalpha():
                 # Short non-alphabetic text like "a=", not word beginnings like "Zw"
                 is_artifact = True