diff --git a/emulators/jazz2-native.yml b/emulators/jazz2-native.yml
index 7b4be7d3..ff09da49 100644
--- a/emulators/jazz2-native.yml
+++ b/emulators/jazz2-native.yml
@@ -45,6 +45,7 @@ files:
   # ================================================================
 
   - name: "Animations/"
+    type: directory
     category: game_data
     path: "jazz2/Content/Animations/"
     standalone_path: "Content/Animations/"
@@ -54,6 +55,7 @@ files:
     note: "Native graphics, sounds and the UI fonts, opened through OpenContentFile."
 
   - name: "Metadata/"
+    type: directory
     category: game_data
     path: "jazz2/Content/Metadata/"
     standalone_path: "Content/Metadata/"
@@ -63,6 +65,7 @@ files:
     note: "Actor .res descriptors (Common, Enemy, Player, UI, Boss, ...)."
 
   - name: "Translations/"
+    type: directory
     category: game_data
     path: "jazz2/Content/Translations/"
     standalone_path: "Content/Translations/"
diff --git a/emulators/mkxp_z.yml b/emulators/mkxp_z.yml
index 3cea7053..57451b8c 100644
--- a/emulators/mkxp_z.yml
+++ b/emulators/mkxp_z.yml
@@ -26,6 +26,7 @@ notes: |
 
 files:
   - name: "Standard"
+    type: directory
     description: "RPG Maker XP Run-Time Package"
     category: game_data
     path: "mkxp-z/RTP/Standard/"
@@ -33,6 +34,7 @@ files:
     source_ref: "src/core.cpp:1081-1124, src/core.cpp:1126-1197"
 
   - name: "RPGVX"
+    type: directory
     description: "RPG Maker VX Run-Time Package"
     category: game_data
     path: "mkxp-z/RTP/RPGVX/"
@@ -40,6 +42,7 @@ files:
     source_ref: "src/core.cpp:1081-1124, src/core.cpp:1126-1197"
 
   - name: "RPGVXAce"
+    type: directory
     description: "RPG Maker VX Ace Run-Time Package"
     category: game_data
     path: "mkxp-z/RTP/RPGVXAce/"
@@ -47,6 +50,7 @@ files:
     source_ref: "src/core.cpp:1081-1124, src/core.cpp:1126-1197"
 
   - name: "Fonts"
+    type: directory
     description: "Fallback font directory (.otf/.ttf)"
     category: game_data
     path: "mkxp-z/Fonts/"
@@ -54,6 +58,7 @@ files:
     source_ref: "src/core.cpp:1199-1211"
 
   - name: "Preload"
+    type: directory
     description: "Ruby scripts loaded before game scripts"
     category: game_data
     path: "mkxp-z/Scripts/Preload/"
@@ -61,6 +66,7 @@ files:
     source_ref: "src/core.cpp:891-934"
 
   - name: "Postload"
+    type: directory
     description: "Ruby scripts loaded after game scripts (RGSS3 only)"
     category: game_data
     path: "mkxp-z/Scripts/Postload/"
diff --git a/emulators/nestopia.yml b/emulators/nestopia.yml
index 269d7b42..afd53bb8 100644
--- a/emulators/nestopia.yml
+++ b/emulators/nestopia.yml
@@ -67,6 +67,7 @@ files:
 
   # --- ADPCM audio samples (optional, game-specific) ---
   - name: "nestopia/samples/moepro/"
+    type: directory
     system: nintendo-nes
     description: "Moero Pro Yakyuu audio samples (16 .wav files, 00.wav-15.wav)"
     required: false
@@ -74,6 +75,7 @@ files:
     source_ref: "libretro/libretro.cpp:183-391 (load_wav), libretro/libretro.cpp:451 (LOAD_SAMPLE_MOERO_PRO_YAKYUU callback), source/core/NstSoundPlayer.hpp:49 (16 samples)"
 
   - name: "nestopia/samples/moepro88/"
+    type: directory
     system: nintendo-nes
     description: "Moero Pro Yakyuu '88 audio samples (20 .wav files, 00.wav-19.wav)"
     required: false
@@ -81,6 +83,7 @@ files:
     source_ref: "libretro/libretro.cpp:183-391 (load_wav), libretro/libretro.cpp:453 (LOAD_SAMPLE_MOERO_PRO_YAKYUU_88 callback), source/core/NstSoundPlayer.hpp:50 (20 samples)"
 
   - name: "nestopia/samples/mptennis/"
+    type: directory
     system: nintendo-nes
     description: "Moero Pro Tennis audio samples (19 .wav files, 00.wav-18.wav)"
     required: false
@@ -88,6 +91,7 @@ files:
     source_ref: "libretro/libretro.cpp:183-391 (load_wav), libretro/libretro.cpp:455 (LOAD_SAMPLE_MOERO_PRO_TENNIS callback), source/core/NstSoundPlayer.hpp:51 (19 samples)"
 
   - name: "nestopia/samples/terao/"
+    type: directory
     system: nintendo-nes
     description: "Terao no Dosukoi Oozumou audio samples (6 .wav files, 00.wav-05.wav)"
     required: false
@@ -95,6 +99,7 @@ files:
     source_ref: "libretro/libretro.cpp:183-391 (load_wav), libretro/libretro.cpp:457 (LOAD_SAMPLE_TERAO_NO_DOSUKOI_OOZUMOU callback), source/core/NstSoundPlayer.hpp:52 (6 samples)"
 
   - name: "nestopia/samples/ftaerobi/"
+    type: directory
     system: nintendo-nes
     description: "Aerobics Studio audio samples (8 .wav files, 00.wav-07.wav)"
     required: false
diff --git a/emulators/nxengine.yml b/emulators/nxengine.yml
index 96cf6d87..c3913136 100644
--- a/emulators/nxengine.yml
+++ b/emulators/nxengine.yml
@@ -50,6 +50,7 @@ files:
 
   - name: "data/"
     path: "nxengine/data/"
+    type: directory
     category: game_data
     system: cave-story
     description: "Full game asset directory tree (399 files: sprites, NPC sheets, stage maps, scripts, backgrounds)"
diff --git a/emulators/o2em.yml b/emulators/o2em.yml
index 1d3de452..b158c74d 100644
--- a/emulators/o2em.yml
+++ b/emulators/o2em.yml
@@ -81,6 +81,7 @@ files:
     source_ref: "libretro.c:1162-1167"
 
   - name: "voice/"
+    type: directory
     required: false
     category: game_data
     note: "The Voice speech synthesis WAV samples. 9 banks (E4, E8-EF) × 128 samples."
diff --git a/emulators/thextech.yml b/emulators/thextech.yml
index 1f714c95..5b86f5de 100644
--- a/emulators/thextech.yml
+++ b/emulators/thextech.yml
@@ -90,18 +90,21 @@ files:
   # ================================================================
 
   - name: "graphics/"
+    type: directory
     category: game_data
     required: true
     source_ref: "src/main/asset_pack.cpp:274, 326-327, src/gfx.cpp:121-229, src/load_gfx.cpp:120-123"
     note: "graphics/ui/ must exist for a directory to be scanned as a pack; GFX_t::load rejects the pack when a required UI image is missing."
 
   - name: "sound/"
+    type: directory
     category: game_data
     required: false
     source_ref: "src/sound.cpp:1319"
     note: "SFX directory, files named by sounds.ini. Game runs without sounds."
 
   - name: "music/"
+    type: directory
     category: game_data
     required: false
     source_ref: "src/sound.cpp:1318"
@@ -132,6 +135,7 @@ files:
     note: "Read when intro.lvlx is absent."
 
   - name: "introset/"
+    type: directory
     category: game_data
     required: false
     source_ref: "src/game_main.cpp:194-222, 247"
@@ -150,12 +154,14 @@ files:
     note: "Read when outro.lvlx is absent."
 
   - name: "worlds/"
+    type: directory
     category: game_data
     required: false
     source_ref: "src/main/menu_main.cpp:361-370"
     note: "Episodes shipped with the pack, listed next to the user's worlds directory."
 
   - name: "battle/"
+    type: directory
     category: game_data
     required: false
     source_ref: "src/main/menu_main.cpp:701-706"
diff --git a/schemas/emulator.schema.json b/schemas/emulator.schema.json
index 1fc45500..8e8a9ccd 100644
--- a/schemas/emulator.schema.json
+++ b/schemas/emulator.schema.json
@@ -425,7 +425,11 @@
             "type": "string"
           },
           "type": {
-            "type": "string"
+            "description": "Set on an entry that names a directory the code reads whole. The entry then stands for every file under path.",
+            "type": "string",
+            "enum": [
+              "directory"
+            ]
           },
           "variant_group": {
             "type": "string",
@@ -599,7 +603,38 @@
           "unsourceable": {
             "type": "string"
           }
-        }
+        },
+        "allOf": [
+          {
+            "if": {
+              "properties": {
+                "name": {
+                  "pattern": "/$"
+                }
+              }
+            },
+            "then": {
+              "required": [
+                "type"
+              ]
+            }
+          },
+          {
+            "if": {
+              "required": [
+                "type"
+              ]
+            },
+            "then": {
+              "properties": {
+                "path": {
+                  "type": "string",
+                  "pattern": "/$"
+                }
+              }
+            }
+          }
+        ]
       }
     },
     "source_branch": {
diff --git a/scripts/common.py b/scripts/common.py
index 0c84a827..f290d0f4 100644
--- a/scripts/common.py
+++ b/scripts/common.py
@@ -1116,6 +1116,101 @@ def group_identical_platforms(
     return result
 
 
+_directory_members_cache: dict[int, tuple[dict, dict[str, dict[str, str]]]] = {}
+
+
+def directory_members(db: dict, directory: str) -> dict[str, str]:
+    """Files the collection holds under a directory an emulator reads whole.
+
+    Returns {destination: sha1}, each destination starting with the directory
+    as the profile writes it. The collection and the destination meet on a
+    tail, so the members are the indexed tails that begin with it.
+
+    A generic directory name can sit in two unrelated trees (``voice/``,
+    ``data/``). Members that do not share one parent, or a destination two
+    contents claim, would merge them into one emulator's directory: nothing
+    is returned and the entry stays a reported gap.
+    """
+    tail = directory.strip("/")
+    if not tail:
+        return {}
+    by_path_suffix = db.get("indexes", {}).get("by_path_suffix", {})
+    cached = _directory_members_cache.get(id(by_path_suffix))
+    if cached is None or cached[0] is not by_path_suffix:
+        cached = (by_path_suffix, {})
+        _directory_members_cache[id(by_path_suffix)] = cached
+    if tail in cached[1]:
+        return cached[1][tail]
+
+    prefix = f"{tail}/"
+    infix = f"/{prefix}"
+    held: dict[str, list[str]] = {}
+    parent: dict[str, str] = {}
+    for key, sha1s in by_path_suffix.items():
+        if key.startswith(prefix):
+            held[key] = sha1s
+            continue
+        at = key.find(infix)
+        if at > 0:
+            member = key[at + 1:]
+            if len(key[:at]) > len(parent.get(member, "")):
+                parent[member] = key[:at]
+    held = {
+        dest: sha1s for dest, sha1s in held.items() if "/.variants/" not in dest
+    }
+    one_tree = len({parent.get(dest, "") for dest in held}) <= 1
+    one_content = all(len(sha1s) == 1 for sha1s in held.values())
+    members = (
+        {dest: held[dest][0] for dest in sorted(held)}
+        if one_tree and one_content
+        else {}
+    )
+    cached[1][tail] = members
+    return members
+
+
+def expand_directory_entries(
+    files: list[dict], db: dict, standalone: bool = False
+) -> list[dict]:
+    """Replace each ``type: directory`` entry by the files held under it.
+
+    A profile declares the directory its code walks; what a pack can carry
+    is the files. Each member keeps the entry's fields and is pinned to the
+    content the collection holds at that destination. A directory nothing
+    answers is kept as declared, one gap, and a member the profile also
+    names as a file is left to that entry.
+    """
+    def destination(entry: dict) -> str:
+        chosen = entry.get("standalone_path") if standalone else None
+        return chosen or entry.get("path") or entry.get("name", "")
+
+    if not any(entry.get("type") == "directory" for entry in files):
+        return files
+    named = {
+        destination(entry) for entry in files if entry.get("type") != "directory"
+    }
+    expanded: list[dict] = []
+    for entry in files:
+        if entry.get("type") != "directory":
+            expanded.append(entry)
+            continue
+        members = directory_members(db, destination(entry))
+        if not members:
+            expanded.append(entry)
+            continue
+        inherited = {
+            key: value
+            for key, value in entry.items()
+            if key not in ("type", "standalone_path")
+        }
+        expanded.extend(
+            {**inherited, "name": dest, "path": dest, "sha1": sha1}
+            for dest, sha1 in members.items()
+            if dest not in named
+        )
+    return expanded
+
+
 def runs_standalone(
     emu_name: str, profile: dict, standalone_cores: set[str]
 ) -> bool:
diff --git a/scripts/generate_pack.py b/scripts/generate_pack.py
index 05ce3417..146db1ee 100644
--- a/scripts/generate_pack.py
+++ b/scripts/generate_pack.py
@@ -36,6 +36,7 @@ from common import (
     build_zip_contents_index,
     check_inside_zip,
     compute_hashes,
+    expand_directory_entries,
     expand_platform_declared_names,
     fetch_large_file,
     filter_systems_by_target,
@@ -1288,7 +1289,11 @@ def generate_emulator_pack(
     with zipfile.ZipFile(zip_path, "w", zipfile.ZIP_DEFLATED) as zf:
         for emu_name, profile in sorted(selected):
             pack_structure = profile.get("pack_structure")
-            files = filter_files_by_mode(profile.get("files", []), standalone)
+            files = expand_directory_entries(
+                filter_files_by_mode(profile.get("files", []), standalone),
+                db,
+                standalone,
+            )
             # A tree only one build reads follows that build, like a file.
             for dd in filter_files_by_mode(
                 profile.get("data_directories", []), standalone
diff --git a/scripts/verify.py b/scripts/verify.py
index 04e487d9..3baa89e5 100644
--- a/scripts/verify.py
+++ b/scripts/verify.py
@@ -38,6 +38,7 @@ from common import (
     build_zip_contents_index,
     check_inside_zip,
     compute_hashes,
+    expand_directory_entries,
     expand_platform_declared_names,
     filter_systems_by_target,
     group_identical_platforms,
@@ -458,7 +459,9 @@ def find_undeclared_files(
 
         is_standalone = runs_standalone(emu_name, profile, standalone_set)
 
-        for f in profile.get("files", []):
+        for f in expand_directory_entries(
+            profile.get("files", []), db, is_standalone
+        ):
             fname = f.get("name", "")
             effective_path = (
                 f.get("standalone_path") if is_standalone else f.get("path")
@@ -1363,7 +1366,11 @@ def verify_emulator(
         )
 
     for emu_name, profile in selected:
-        files = filter_files_by_mode(profile.get("files", []), standalone)
+        files = expand_directory_entries(
+            filter_files_by_mode(profile.get("files", []), standalone),
+            db,
+            standalone,
+        )
         if region_drops:
             files = [
                 fe
diff --git a/tests/test_directory_entries.py b/tests/test_directory_entries.py
new file mode 100644
index 00000000..9f5ae507
--- /dev/null
+++ b/tests/test_directory_entries.py
@@ -0,0 +1,296 @@
+"""A profile entry that names a directory stands for the files under it.
+
+Some cores read a whole tree: EasyRPG looks for an RTP under `rtp/2000/`,
+O2EM for speech samples under `voice/`. The profile declares the directory,
+the collection holds the files, and for a long time nothing joined the two:
+the entry was resolved as one file called `rtp/2000/`, found nowhere, and
+reported missing while 3 584 collected files stayed out of every pack.
+"""
+
+from __future__ import annotations
+
+import hashlib
+import json
+import sys
+import tempfile
+import unittest
+import zipfile
+from pathlib import Path
+
+import yaml
+
+REPO_ROOT = Path(__file__).resolve().parent.parent
+sys.path.insert(0, str(REPO_ROOT / "scripts"))
+
+import common  # noqa: E402
+import generate_db  # noqa: E402
+import generate_pack as builder  # noqa: E402
+import verify  # noqa: E402
+
+PROFILE = """\
+emulator: Demo
+type: libretro
+display_name: Demo
+systems: [demo-system]
+cores: [demo]
+files:
+  - name: "RTP 2000"
+    path: "rtp/2000/"
+    type: directory
+    category: game_data
+    required: false
+  - name: "Fonts"
+    path: "demo/Fonts/"
+    type: directory
+    category: game_data
+    required: false
+"""
+
+PLATFORM = {
+    "platform": "Demo",
+    "verification_mode": "existence",
+    "base_destination": "",
+    "cores": ["demo"],
+    "systems": {
+        "demo-system": {
+            "files": [{"name": "boot.bin", "destination": "boot.bin"}],
+        },
+    },
+}
+
+
+class DirectoryFixture(unittest.TestCase):
+    def setUp(self):
+        self._tmp = tempfile.TemporaryDirectory()
+        self.root = Path(self._tmp.name)
+        self.bios = self.root / "bios"
+        self.emulators = self.root / "emulators"
+        self.platforms = self.root / "platforms"
+        for directory in (self.bios, self.emulators, self.platforms):
+            directory.mkdir()
+        self.files: dict[str, dict] = {}
+        self.sha1: dict[str, str] = {}
+
+        self._add("SystemA/boot.bin", b"boot")
+        self._add("Engine/demo/rtp/2000/Backdrop/a.png", b"backdrop")
+        self._add("Engine/demo/rtp/2000/Music/b.mid", b"music")
+        self._add("Engine/demo/rtp/2000/.variants/a.png.1234", b"older backdrop")
+
+        (self.platforms / "demo.yml").write_text(yaml.dump(PLATFORM))
+        (self.platforms / "_registry.yml").write_text(
+            yaml.dump({"platforms": {"demo": {"status": "active"}}})
+        )
+        common._emulator_profiles_cache.clear()
+
+    def tearDown(self):
+        common._emulator_profiles_cache.clear()
+        self._tmp.cleanup()
+
+    def _add(self, relative: str, payload: bytes) -> None:
+        path = self.bios / relative
+        path.parent.mkdir(parents=True, exist_ok=True)
+        path.write_bytes(payload)
+        sha1 = hashlib.sha1(payload).hexdigest()
+        self.sha1[relative] = sha1
+        self.files[sha1] = {
+            "path": f"bios/{relative}",
+            "name": path.name,
+            "size": len(payload),
+            "sha1": sha1,
+            "md5": hashlib.md5(payload).hexdigest(),
+            "sha256": hashlib.sha256(payload).hexdigest(),
+            "crc32": f"{len(payload):08x}",
+        }
+
+    def _db(self) -> dict:
+        """The index generate_db builds, over files stored where the test put them."""
+        indexes = generate_db.build_indexes(self.files, {})
+        stored = {
+            sha1: {**record, "path": str(self.root / record["path"])}
+            for sha1, record in self.files.items()
+        }
+        return {"files": stored, "indexes": indexes}
+
+    def _profiles(self, body: str = PROFILE) -> dict:
+        (self.emulators / "demo.yml").write_text(body)
+        common._emulator_profiles_cache.clear()
+        return common.load_emulator_profiles(str(self.emulators))
+
+
+class DirectoryMembers(DirectoryFixture):
+    def test_every_file_under_the_tail_is_a_member(self):
+        self.assertEqual(
+            common.directory_members(self._db(), "rtp/2000/"),
+            {
+                "rtp/2000/Backdrop/a.png": self.sha1[
+                    "Engine/demo/rtp/2000/Backdrop/a.png"
+                ],
+                "rtp/2000/Music/b.mid": self.sha1["Engine/demo/rtp/2000/Music/b.mid"],
+            },
+        )
+
+    def test_a_directory_nobody_collected_has_no_member(self):
+        self.assertEqual(common.directory_members(self._db(), "demo/Fonts/"), {})
+
+    def test_two_trees_answering_one_tail_prove_nothing(self):
+        """`voice/` under two unrelated parents is two directories, and merging
+        them would hand one emulator the other's files."""
+        self._add("Console/voice/E480.WAV", b"speech")
+        self._add("Other/app/voice/hello.wav", b"another program")
+        self.assertEqual(common.directory_members(self._db(), "voice/"), {})
+
+    def test_one_tree_under_a_generic_name_is_enough(self):
+        self._add("Console/voice/E480.WAV", b"speech")
+        self.assertEqual(
+            common.directory_members(self._db(), "voice/"),
+            {"voice/E480.WAV": self.sha1["Console/voice/E480.WAV"]},
+        )
+
+
+class CrossReferenceReadsADirectory(DirectoryFixture):
+    def _report(self, body: str = PROFILE) -> list[dict]:
+        profiles = self._profiles(body)
+        return verify.find_undeclared_files(
+            PLATFORM, str(self.emulators), self._db(), profiles
+        )
+
+    def test_each_held_file_is_reported_as_held(self):
+        held = {
+            entry["path"]: entry["sha1"]
+            for entry in self._report()
+            if entry["in_repo"]
+        }
+        self.assertEqual(
+            held,
+            {
+                "rtp/2000/Backdrop/a.png": self.sha1[
+                    "Engine/demo/rtp/2000/Backdrop/a.png"
+                ],
+                "rtp/2000/Music/b.mid": self.sha1["Engine/demo/rtp/2000/Music/b.mid"],
+            },
+        )
+
+    def test_a_directory_with_nothing_collected_stays_one_gap(self):
+        gaps = [entry for entry in self._report() if not entry["in_repo"]]
+        self.assertEqual([(g["name"], g["path"]) for g in gaps], [("Fonts", "demo/Fonts/")])
+
+    def test_a_file_the_profile_also_names_is_reported_once(self):
+        body = PROFILE + (
+            '  - name: "b.mid"\n'
+            '    path: "rtp/2000/Music/b.mid"\n'
+            "    category: game_data\n"
+            "    required: true\n"
+        )
+        paths = [entry["path"] for entry in self._report(body)]
+        self.assertEqual(paths.count("rtp/2000/Music/b.mid"), 1)
+
+
+class PackCarriesADirectory(DirectoryFixture):
+    EXPECTED = {"rtp/2000/Backdrop/a.png", "rtp/2000/Music/b.mid"}
+
+    def test_a_platform_pack_ships_the_tree(self):
+        profiles = self._profiles()
+        out = self.root / "dist"
+        out.mkdir()
+        zip_path = builder.generate_pack(
+            "demo", str(self.platforms), self._db(), str(self.bios), str(out),
+            include_extras=True, emulators_dir=str(self.emulators),
+            emu_profiles=profiles, offline=True,
+        )
+        with zipfile.ZipFile(zip_path) as archive:
+            names = set(archive.namelist())
+            self.assertEqual(
+                archive.read("rtp/2000/Backdrop/a.png"), b"backdrop"
+            )
+        self.assertTrue(self.EXPECTED <= names, sorted(names))
+        self.assertFalse([n for n in names if ".variants" in n])
+
+    def test_the_install_manifest_lists_the_tree(self):
+        profiles = self._profiles()
+        manifest = builder.generate_manifest(
+            "demo", str(self.platforms), self._db(), str(self.bios),
+            str(self.platforms / "_registry.yml"),
+            emulators_dir=str(self.emulators), emu_profiles=profiles,
+            offline=True,
+        )
+        dests = {entry["dest"] for entry in manifest["files"]}
+        self.assertTrue(self.EXPECTED <= dests, sorted(dests))
+        json.dumps(manifest)
+
+    def test_an_emulator_pack_ships_the_tree(self):
+        self._profiles()
+        out = self.root / "emu"
+        out.mkdir()
+        zip_path = builder.generate_emulator_pack(
+            ["demo"], str(self.emulators), self._db(), str(self.bios), str(out),
+            offline=True,
+        )
+        with zipfile.ZipFile(zip_path) as archive:
+            names = set(archive.namelist())
+        self.assertTrue(self.EXPECTED <= names, sorted(names))
+
+    def test_verify_counts_what_the_emulator_pack_ships(self):
+        self._profiles()
+        result = verify.verify_emulator(["demo"], str(self.emulators), self._db())
+        held = {
+            detail["name"]
+            for detail in result["details"]
+            if detail["status"] == verify.Status.OK
+        }
+        self.assertEqual(held, self.EXPECTED)
+        missing = [
+            detail["name"]
+            for detail in result["details"]
+            if detail["status"] == verify.Status.MISSING
+        ]
+        self.assertEqual(missing, ["Fonts"])
+
+
+class ProfileContract(unittest.TestCase):
+    """One way to say an entry is a directory, so one place reads it."""
+
+    def _errors(self, entry: dict) -> list[str]:
+        from jsonschema import Draft202012Validator
+
+        schema = json.loads(
+            (REPO_ROOT / "schemas" / "emulator.schema.json").read_text()
+        )
+        validator = Draft202012Validator(schema["properties"]["files"]["items"])
+        return [error.message for error in validator.iter_errors(entry)]
+
+    def test_a_name_that_is_a_directory_must_say_so(self):
+        self.assertTrue(self._errors({"name": "voice/"}))
+        self.assertEqual(self._errors({"name": "voice/", "type": "directory"}), [])
+
+    def test_the_marker_takes_no_other_value(self):
+        self.assertTrue(self._errors({"name": "RTP", "path": "rtp/", "type": "folder"}))
+
+    def test_a_directory_is_written_with_its_trailing_slash(self):
+        self.assertTrue(
+            self._errors({"name": "RTP", "path": "rtp/2000", "type": "directory"})
+        )
+        self.assertEqual(
+            self._errors({"name": "RTP", "path": "rtp/2000/", "type": "directory"}),
+            [],
+        )
+
+    def test_every_profile_follows_it(self):
+        offenders = []
+        for path in sorted((REPO_ROOT / "emulators").glob("*.yml")):
+            document = yaml.safe_load(path.read_text(encoding="utf-8")) or {}
+            for entry in document.get("files") or []:
+                if self._errors_for_directory_rules(entry):
+                    offenders.append(f"{path.name}: {entry.get('name')}")
+        self.assertEqual(offenders, [])
+
+    @staticmethod
+    def _errors_for_directory_rules(entry: dict) -> bool:
+        name = str(entry.get("name", ""))
+        path = entry.get("path")
+        if entry.get("type") == "directory":
+            return isinstance(path, str) and not path.endswith("/")
+        return name.endswith("/") or "type" in entry
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/wiki/profiling.md b/wiki/profiling.md
index a5a278a3..b5fe28f4 100644
--- a/wiki/profiling.md
+++ b/wiki/profiling.md
@@ -372,6 +372,7 @@ which CI validates every profile against.
 | `load_from` | directory the core reads the file from when it is not the system directory |
 | `source_ref` | source file and line number (e.g. `boot.cpp:42`), read at the profile's `source_commit` when set. A dict splits `standalone` from `libretro` when they diverge |
 | `path` | destination path relative to system directory |
+| `type` | `directory` when the code reads a whole tree (an RTP, a folder of speech samples). `path` is then the directory, written with its trailing slash, and the entry stands for every file the collection holds under it. A name ending in `/` requires it |
 | `description` | what this file is |
 | `note` | additional context |
 | `contents` | structure of files inside a BIOS ZIP (`name`, `description`, `size`, `crc32`) |