diff --git a/install/batocera.json b/install/batocera.json
index 8c24297c0..114a811ab 100644
--- a/install/batocera.json
+++ b/install/batocera.json
@@ -1841,8 +1841,7 @@
       "reason": "not_found",
       "cores": [
         "dosbox-x"
-      ],
-      "held": true
+      ]
     },
     {
       "dest": "extras.wad",
diff --git a/install/knulli.json b/install/knulli.json
index 25b3ccce4..f06163712 100644
--- a/install/knulli.json
+++ b/install/knulli.json
@@ -1598,8 +1598,7 @@
       "reason": "not_found",
       "cores": [
         "dosbox-x"
-      ],
-      "held": true
+      ]
     },
     {
       "dest": "extras.wad",
diff --git a/scripts/cross_reference.py b/scripts/cross_reference.py
index 71ac29ed9..08e1b74be 100644
--- a/scripts/cross_reference.py
+++ b/scripts/cross_reference.py
@@ -26,7 +26,9 @@ sys.path.insert(0, os.path.dirname(__file__))
 from common import (
     platform_arg,
     ProfileSelectionError,
+    _foreign_tree,
     _norm_system_id,
+    _owner_tokens,
     archive_entry,
     directory_members,
     expand_directory_entries,
@@ -215,8 +217,14 @@ def _resolve_source(
     none of the hashes the entry declares: a name never wins over a declared
     hash, and zquestclassic's ending.mid read as held because Hydra Castle
     Labyrinth has another file of that name.
+
+    Another casing of the name in another emulator's tree proves nothing, as
+    in resolve_local_file's case-insensitive step: dosbox-x's et4000.bin read
+    as held through pcem's et4000.BIN, which the pack and the installer
+    refuse it.
     """
     declared = _declared_content(file_entry or {})
+    owners = _owner_tokens(file_entry or {})
 
     def _can_be(sha1s: list | str) -> bool:
         if not file_entry or db_files is None:
@@ -233,6 +241,14 @@ def _resolve_source(
         """Whether the files indexed under *name* can be this entry."""
         return _can_be(by_name.get(name) or [])
 
+    def _folded_hit(name: str) -> bool:
+        """_name_hit for a name matched in another casing."""
+        return _can_be([
+            sha1 for sha1 in by_name.get(name) or []
+            if db_files is None
+            or not _foreign_tree(db_files.get(sha1, {}).get("path", ""), owners)
+        ])
+
     # bios/ via database.json by_name
     if fname in by_name and _name_hit(fname):
         return "bios"
@@ -241,10 +257,10 @@ def _resolve_source(
     if basename and basename in by_name and _name_hit(basename):
         return "bios"
     key = fname.lower()
-    if key in by_name_lower and _name_hit(by_name_lower[key]):
+    if key in by_name_lower and _folded_hit(by_name_lower[key]):
         return "bios"
     if basename:
-        if basename.lower() in by_name_lower and _name_hit(
+        if basename.lower() in by_name_lower and _folded_hit(
             by_name_lower[basename.lower()]
         ):
             return "bios"
@@ -257,7 +273,7 @@ def _resolve_source(
     if canonical and canonical != fname:
         if canonical in by_name and _name_hit(canonical):
             return "bios"
-        if canonical.lower() in by_name_lower and _name_hit(
+        if canonical.lower() in by_name_lower and _folded_hit(
             by_name_lower[canonical.lower()]
         ):
             return "bios"
@@ -901,7 +917,9 @@ def _cross_reference_profile(
         source = next(
             (
                 found for version in versions[slot]
-                if (found := entry_source(version, index)) is not None
+                if (found := entry_source(
+                    {**version, "source_profile": emu_name}, index,
+                )) is not None
             ),
             "missing",
         )
diff --git a/scripts/generate_site.py b/scripts/generate_site.py
index 32f926da0..4e206261e 100644
--- a/scripts/generate_site.py
+++ b/scripts/generate_site.py
@@ -9416,7 +9416,7 @@ def _hash_spans(value: str | list, copy: bool = False) -> str:
 
 
 def _availability_check(
-    db: dict, data_names: set[str] | None
+    db: dict, data_names: set[str] | None, owner: str = "",
 ) -> Callable[[dict], bool]:
     """A predicate answering whether the collection holds a file.
 
@@ -9447,7 +9447,7 @@ def _availability_check(
         # under the name belongs to another game or release.
         if not f.get("name") or f.get("unsourceable"):
             return False
-        return entry_source(f, index) is not None
+        return entry_source({**f, "source_profile": owner} if owner else f, index) is not None
 
     return _file_available
 
@@ -10180,7 +10180,7 @@ def emulator_pages(
             lines.append("")
             lines.extend(markup.aside("info", "Why no files", [_escape_tags(str(exclusion))])[:-1])
     else:
-        _file_available = _availability_check(db, data_names)
+        _file_available = _availability_check(db, data_names, name)
 
         lines.extend(["## Files", ""])
         lines.extend(_emulator_file_summary(files))
diff --git a/scripts/verify.py b/scripts/verify.py
index 8689a4dcf..b465ab4bc 100644
--- a/scripts/verify.py
+++ b/scripts/verify.py
@@ -667,13 +667,18 @@ def find_undeclared_files(
                 # Resolution: name, then path basename
                 # storage: release names where the bytes are served from, not
                 # that the collection holds them: resolved like any file.
+                # Resolved as the asker, as the builder's ExtraResolver does:
+                # another casing of the name in another emulator's tree is
+                # not this emulator's file (dosbox-x's et4000.bin and pcem's
+                # et4000.BIN).
+                owned = {**f, "source_profile": emu_name}
                 if shipped_on_mismatch and (f.get("md5") or f.get("sha1")):
                     # The entry states what its content should be and the builder
                     # drops a copy that contradicts it, so content decides here
                     # too. A name match would not do: generic names collide across
                     # systems, and answering yes on one describes a pack that will
                     # not contain the file.
-                    _lp, _st = resolve_local_file(f, db, dest_hint=dest)
+                    _lp, _st = resolve_local_file(owned, db, dest_hint=dest)
                     in_repo = _lp is not None and _st != "hash_mismatch"
                 else:
                     in_repo = _name_in_index(
@@ -693,8 +698,8 @@ def find_undeclared_files(
                         # rejects them all. NanoBoyAdvance's 16 KB bios.bin met
                         # only PCem's and QEMU's PC BIOS images of that name.
                         # The fallback below then decides as for any mismatch.
-                        _lp, _st = resolve_local_file(f, db, dest_hint=dest)
-                        if _st == "hash_mismatch":
+                        _lp, _st = resolve_local_file(owned, db, dest_hint=dest)
+                        if _st == "hash_mismatch" or _lp is None:
                             in_repo = False
                     if not in_repo:
                         # Hash fallback: the repo may hold the content under a
@@ -707,7 +712,7 @@ def find_undeclared_files(
                         # frontend would reject it, the builder leaves it out, and
                         # calling it available here would describe a pack that
                         # does not contain it.
-                        _lp, _st = resolve_local_file(f, db, dest_hint=dest)
+                        _lp, _st = resolve_local_file(owned, db, dest_hint=dest)
                         in_repo = _st != "not_found" and _lp is not None
                         if in_repo and _st == "hash_mismatch" and shipped_on_mismatch:
                             in_repo = False
@@ -717,7 +722,7 @@ def find_undeclared_files(
                         # held for it, the rule the builder's lookup applies
                         # (packextras.ExtraResolver). The Apple IIGS' 128 KB
                         # ROM is not Basilisk II's ROM.
-                        _lp, _st = resolve_local_file(f, db, dest_hint=dest)
+                        _lp, _st = resolve_local_file(owned, db, dest_hint=dest)
                         if core_size_refusal(
                             f, _lp, same_slot_entries(profile.get("files"), fname, dest)
                         ):
diff --git a/tests/test_foreign_tree_names.py b/tests/test_foreign_tree_names.py
index 2be75d71b..360060add 100644
--- a/tests/test_foreign_tree_names.py
+++ b/tests/test_foreign_tree_names.py
@@ -185,5 +185,53 @@ class RetailDashboardTree(unittest.TestCase):
                     self.assertEqual(status, "path_exact", path)
 
 
+class TheGapReportAsksAsTheEmulator(unittest.TestCase):
+    """dosbox-x's et4000.bin, no hash: pcem's et4000.BIN was its only
+    casing. The resolver, asked as dosbox-x, refuses it and the pack and the
+    installer leave the file out, while the gap report, verify's core files
+    and the manifest's held flag counted it available."""
+
+    _hold = ForeignTreeNames._hold
+
+    def setUp(self):
+        ForeignTreeNames.setUp(self)
+        self._hold("bios/Other/pcem/roms/et4000.BIN", b"E" * 64)
+        self.entry = {"name": "et4000.bin", "required": True}
+
+    def _source(self, owner: str) -> str | None:
+        from cross_reference import entry_source
+
+        by_name = self.db["indexes"]["by_name"]
+        index = {
+            "by_name": by_name, "by_name_lower": {k.lower(): k for k in by_name},
+            "by_path_suffix": {}, "by_md5": {}, "by_sha256": {}, "by_crc32": {},
+            "db_files": self.db["files"], "data_names": None,
+        }
+        return entry_source({**self.entry, "source_profile": owner}, index)
+
+    def test_another_tree_casing_is_not_held(self):
+        self.assertIsNone(self._source("dosbox-x"))
+        entry = {**self.entry, "source_profile": "dosbox-x"}
+        self.assertEqual(resolve_local_file(entry, self.db), (None, "not_found"))
+
+    def test_the_tree_owner_holds_it(self):
+        self.assertEqual(self._source("pcem"), "bios")
+
+    def test_core_files_follow_the_resolver(self):
+        from verify import find_undeclared_files
+
+        profiles = {"dosbox-x": {
+            "emulator": "DOSBox-X", "type": "libretro", "systems": ["dos"],
+            "files": [self.entry],
+        }}
+        config = {"platform": "P", "verification_mode": "md5", "cores": ["dosbox-x"],
+                  "systems": {"dos": {"files": []}}}
+        (found,) = [
+            u for u in find_undeclared_files(config, "emulators", self.db, profiles)
+            if u["name"] == "et4000.bin"
+        ]
+        self.assertFalse(found["in_repo"])
+
+
 if __name__ == "__main__":
     unittest.main()