diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7be2f4c2..471cabb9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,11 @@
 
 ### 고침
 
+- 줄 캐시(`write_line_caches`)가 머리에 정의되지 않은 글머리표·번호를 가리키는 문단 모양(예: 글머리표 idRef 0)의
+  문단에는 캐시를 쓰지 않는다. 한/글은 정의가 없어도 글머리 자리를 잡아 첫 줄에 글자를 덜 넣는데, 전에는 글머리 없이
+  나눈 줄을 써서 한/글이 그 줄을 눌러 담을 수 있었다.
+- 줄 캐시가 왼쪽이나 오른쪽 여백이 음수인 문단(줄이 단·칸 가장자리 밖으로 나가는 문단)에도 캐시를 쓰지 않는다. 한/글이
+  그런 줄을 어떤 폭으로 나누는지 확정하지 못했고, 한 글자 이상 다르게 나눈 문단이 있었다.
 - 쪽 수 추정이 표 칸 안에서 양쪽에 글 자리가 있는 어울림 개체 곁에 빈 줄만 오는 칸도 추정한다. 한/글처럼 빈 줄은 개체 곁에
   한 높이 두 조각으로 둔다(곁에 글이 오면 지금처럼 지원 밖). 한/글이 저장한 줄 캐시가 있는 칸에서 그런 두 조각을 줄 둘로
   세어 칸을 조각 수만큼 높게 잡던 것도 바로잡았다.
diff --git a/src/hwpx/layout/line_cache.py b/src/hwpx/layout/line_cache.py
index cd547d39..88299c89 100644
--- a/src/hwpx/layout/line_cache.py
+++ b/src/hwpx/layout/line_cache.py
@@ -52,7 +52,8 @@
 for, a word too long for a line, a line break that moves when every line is laid out :data:`_MARGIN` narrower or
 wider (a line ending that close to its room may end elsewhere in Hancom), or a tab whose text before it is closer
 to a tab stop than a layout unit for each character since the line's start or the last tab stop (at most
-:data:`_MARGIN`). A paragraph that has a cache keeps it. A document mixing paragraphs with and without a cache is
+:data:`_MARGIN`), a paragraph shape naming a bullet or a number the header does not define (Hancom draws a label
+there all the same), or one with a negative left or right margin. A paragraph that has a cache keeps it. A document mixing paragraphs with and without a cache is
 laid out as one. Nothing is written when the estimate does not follow the document.
 """
 
@@ -260,7 +261,8 @@ def _picture_lines(measure: Any, paragraph: Any, width: int) -> tuple[list[dict[
         return None
     vertical = _vertical_align(measure, paragraph.get("paraPrIDRef"))
     shape = measure.shape(paragraph.get("paraPrIDRef"))
-    if vertical not in _BASELINES or shape.font_line:
+    if vertical not in _BASELINES or shape.font_line or _unknown_label(measure, paragraph.get("paraPrIDRef")) \
+            or shape.left < 0 or shape.right < 0:
         return None
     room = width - shape.left - shape.right
     headed = measure.headed(paragraph)
@@ -463,6 +465,11 @@ def _lines(measure: Any, paragraph: Any, width: int, *, first: bool,
     vertical = _vertical_align(measure, paragraph.get("paraPrIDRef"))
     if shape.font_line or vertical not in _BASELINES or not _shapes_sure(measure, paragraph, runs):
         return None
+    if _unknown_label(measure, paragraph.get("paraPrIDRef")):
+        return None  # a bullet or number the header does not define: Hancom draws a label all the same
+    if shape.left < 0 or shape.right < 0:
+        return None  # a margin reaching past the column's or the cell's edge: how wide Hancom lays the lines out
+        # then was not pinned down
     if measure.pictured(paragraph.get("paraPrIDRef")):
         return None  # a picture bullet sized by its picture: its room was not measured
     size, refs, sizes = _pages._text_size(measure, runs)
@@ -604,6 +611,25 @@ def _shapes_sure(measure: Any, paragraph: Any, runs: list[Any]) -> bool:
     return True
 
 
+def _unknown_label(measure: Any, para_pr_id: str | None) -> bool:
+    """Whether a paragraph shape *para_pr_id* heads its paragraphs with a bullet or a number the header does not
+    define (``hh:heading`` naming no ``hh:bullet`` or ``hh:numbering``): Hancom still draws a label before their
+    text, of a room not known here."""
+
+    unknown = getattr(measure, "_line_cache_unknown_labels", None)
+    if unknown is None:
+        defined = {"BULLET": {item.get("id") for item in measure._header.iter(f"{HH}bullet")},
+                   "NUMBER": {item.get("id") for item in measure._header.iter(f"{HH}numbering")}}
+        unknown = set()
+        for shape in measure._header.iter(f"{HH}paraPr"):
+            heading = shape.find(f"{HH}heading")
+            if heading is not None and heading.get("type") in defined \
+                    and heading.get("idRef") not in defined[heading.get("type")]:
+                unknown.add(shape.get("id"))
+        measure._line_cache_unknown_labels = unknown
+    return para_pr_id in unknown
+
+
 def _vertical_align(measure: Any, para_pr_id: str | None) -> str | None:
     """Where a paragraph of the shape *para_pr_id* sets its characters in their lines (``hh:align``'s
     ``vertical``): BASELINE (the default), TOP, CENTER or BOTTOM; None for a shape not in the header."""
diff --git a/tests/test_layout_line_cache.py b/tests/test_layout_line_cache.py
index 61e7bc92..8a09d78a 100644
--- a/tests/test_layout_line_cache.py
+++ b/tests/test_layout_line_cache.py
@@ -356,6 +356,37 @@ def test_a_page_control_among_the_text_is_left_for_hancom() -> None:
     assert report.written == 0 and report.skipped == 1
 
 
+@pytest.mark.parametrize("kind", ["BULLET", "NUMBER"])
+def test_a_paragraph_headed_by_a_label_the_header_does_not_define_is_left_for_hancom(kind: str) -> None:
+    # A paragraph shape naming a bullet or a number the header lacks: Hancom still draws a label before the text
+    # (seen with a bullet: its first line holds fewer characters), of a room not known.
+    document = HwpxDocument.new()
+    document.add_paragraph("가나다 " * 40)
+    ref = _body(document)[-1].get("paraPrIDRef")
+    shape = next(s for s in document.oxml.headers[0].element.iter(f"{HH}paraPr") if s.get("id") == ref)
+    shape.find(f"{HH}heading").attrib.update({"type": kind, "idRef": "99"})
+
+    report = write_line_caches(document)
+
+    assert report.written == 0
+
+
+@pytest.mark.parametrize("side", ["left", "right"])
+def test_a_paragraph_with_a_negative_margin_is_left_for_hancom(side: str) -> None:
+    # A margin reaching past the column's edge: Hancom lays such lines out at a width not pinned down (one 500
+    # out on the right, or 339 out on the left in a cell, broke a character or more off FormFit's).
+    document = HwpxDocument.new()
+    document.add_paragraph("가나다 " * 40)
+    ref = _body(document)[-1].get("paraPrIDRef")
+    shape = next(s for s in document.oxml.headers[0].element.iter(f"{HH}paraPr") if s.get("id") == ref)
+    for margin in shape.iter("{http://www.hancom.co.kr/hwpml/2011/core}" + side):
+        margin.set("value", "-500")
+
+    report = write_line_caches(document)
+
+    assert report.written == 0
+
+
 @pytest.mark.parametrize(("condense", "spacing", "written"), [("0", 0, 1), ("10", 0, 0), ("0", -10, 0)])
 def test_a_no_break_space_among_spaces_that_shrink_is_left_for_hancom(condense: str, spacing: int, written: int) -> None:
     # A no-break space in a paragraph with 최소 공백 was seen to break a line elsewhere than FormFit, and one with