diff --git a/README.md b/README.md
index 7d98f84..b57ca09 100644
--- a/README.md
+++ b/README.md
@@ -36,12 +36,12 @@ python fccs_scan.py
 
 Reads the restored FCCS backup directory and writes all drawer IDs (subfolder names) to `drawer_ids.txt`. It also:
 
-- **Flags prefix clashes** — if one drawer ID is a prefix of another (e.g. `02218` and `02218A`), searching the shorter ID in FCCS pops up a selection box that breaks automated navigation. These clashes are reported, and the shorter (prefix) IDs are auto-seeded into `ignore.txt` for review.
+- **Flags prefix clashes** — if one drawer ID is a prefix of another (e.g. `02218` and `02218A`), searching them in FCCS can pop up a selection box that breaks automated navigation. These clashes are reported, and **every drawer in each clash group** is auto-seeded into `ignore.txt` for review.
 - **Reports ignored drawers** — any IDs listed in `ignore.txt` that exist in this backup are shown as ones the export will skip.
 
-**Ignoring drawers:** The scan creates `ignore.txt` (at `ignore_file`, default `C:\Migration\ignore.txt`) if it doesn't exist and pre-fills it with the clash prefixes — searching those in FCCS shows a selection box that stalls the automation, so they're skipped by default. Open the file and:
+**Ignoring drawers:** The scan creates `ignore.txt` (at `ignore_file`, default `C:\Migration\ignore.txt`) if it doesn't exist and pre-fills it with every drawer in each clash group — searching those in FCCS can show a selection box that stalls the automation, so they're skipped by default. Open the file and:
 
-- **Delete or comment out** any clash prefix you actually want exported (then handle it manually in FCCS).
+- **Delete or comment out** any clashing drawer you actually want exported (then handle it manually in FCCS).
 - **Add** any other drawers to skip (e.g. password-protected folders), one ID per line.
 
 Re-running the scan never overwrites your edits — it only appends newly-discovered clashes. `drawer_ids.txt` stays a full inventory; the export skips anything active in the ignore list. Lines starting with `#` are comments.
diff --git a/__pycache__/fccs_scan.cpython-313.pyc b/__pycache__/fccs_scan.cpython-313.pyc
index b210fde..ec8de81 100644
Binary files a/__pycache__/fccs_scan.cpython-313.pyc and b/__pycache__/fccs_scan.cpython-313.pyc differ
diff --git a/fccs_scan.py b/fccs_scan.py
index 597e548..1299714 100644
--- a/fccs_scan.py
+++ b/fccs_scan.py
@@ -19,39 +19,45 @@ _IGNORE_HEADER = [
     "#",
     "# Add password-protected or otherwise-excluded drawers here.",
     "#",
-    "# The IDs auto-added below are prefix clashes: searching them in FCCS",
-    "# pops a selection box that breaks the automation, so they're skipped by",
-    "# default. DELETE or comment out any you actually DO want exported (then",
-    "# handle them manually), and keep the rest.",
+    "# The IDs auto-added below are prefix clashes: searching any of them in",
+    "# FCCS can pop a selection box that breaks the automation, so ALL drawers",
+    "# in each clash group are skipped by default. DELETE or comment out any",
+    "# you actually DO want exported (then handle them manually), keep the rest.",
     "",
 ]
 
 
 def update_ignore_file(ignore_file, clashes, log):
-    """Create ignore.txt if missing and seed it with clash prefix IDs.
+    """Create ignore.txt if missing and seed it with clash-group IDs.
 
-    Never overwrites existing entries — only appends clash prefixes that
-    aren't already present. The shorter (prefix) ID of each clash is the one
-    that triggers the FCCS selection box, so it's the candidate to skip.
-    Returns the list of IDs that were added.
+    Every drawer involved in a clash (both the prefix and each longer ID that
+    matches it) is added, since any of them can trip the FCCS selection box.
+    Never overwrites existing entries — only appends IDs not already present,
+    and de-dupes so no ID is written twice. Returns the list of IDs added.
     """
     existing = set(load_lines(ignore_file))
     file_exists = os.path.exists(ignore_file)
 
-    to_add = [(short, matches) for short, matches in clashes
-              if short not in existing]
+    seen = set(existing)  # never re-add anything already listed
+    blocks = []           # (comment, [new_ids]) to append, in clash order
+    for short, matches in clashes:
+        group = [short] + list(matches)
+        new_ids = [g for g in group if g not in seen]
+        if not new_ids:
+            continue
+        seen.update(new_ids)
+        blocks.append((f"# clash group: {', '.join(group)}", new_ids))
 
     # Existing file already covers every clash — leave it untouched.
-    if file_exists and not to_add:
+    if file_exists and not blocks:
         return []
 
     lines = []
     if not file_exists:
         lines.extend(_IGNORE_HEADER)
-
-    for short, matches in to_add:
-        lines.append(f"# clashes with: {', '.join(matches)}")
-        lines.append(short)
+    for comment, new_ids in blocks:
+        lines.append(comment)
+        lines.extend(new_ids)
 
     mode = "a" if file_exists else "w"
     with open(ignore_file, mode, encoding="utf-8") as f:
@@ -59,11 +65,11 @@ def update_ignore_file(ignore_file, clashes, log):
             f.write("\n")  # separate the new block from prior content
         f.write("\n".join(lines) + "\n")
 
-    added = [short for short, _ in to_add]
+    added = [i for _, ids in blocks for i in ids]
     if not file_exists:
         log(f"Created ignore file: {ignore_file}")
     if added:
-        log(f"Added {len(added)} clash prefix ID(s) to ignore list: "
+        log(f"Added {len(added)} clash-group ID(s) to ignore list: "
             f"{', '.join(added)}")
     return added