diff --git a/drb-c2-core/app/models.py b/drb-c2-core/app/models.py
index e82e797..8eed24c 100644
--- a/drb-c2-core/app/models.py
+++ b/drb-c2-core/app/models.py
@@ -147,6 +147,7 @@ class TripCreate(BaseModel):
     start_date: str  # YYYY-MM-DD
     end_date: str    # YYYY-MM-DD
     available_tags: List[str] = []      # tag labels configured for this trip
+    overlap_tags: List[str] = []        # subset of available_tags that allow time overlap
 
 
 class TripEventCreate(BaseModel):
diff --git a/drb-c2-core/app/routers/trips.py b/drb-c2-core/app/routers/trips.py
index 3c4a420..2410c2e 100644
--- a/drb-c2-core/app/routers/trips.py
+++ b/drb-c2-core/app/routers/trips.py
@@ -208,6 +208,7 @@ async def create_trip(body: TripCreate):
         "end_date": body.end_date,
         "attendees": {},  # {discord_user_id: discord_username}
         "available_tags": body.available_tags,
+        "overlap_tags": body.overlap_tags,
         "created_at": now,
     }
     await fstore.doc_set("trips", trip_id, doc, merge=False)
@@ -226,13 +227,14 @@ async def get_trip(trip_id: str):
 
 @router.put("/{trip_id}/tags")
 async def update_trip_tags(trip_id: str, body: dict):
-    """Replace the trip's available tag list."""
+    """Replace the trip's available tag list and overlap-allowed tag list."""
     trip = await fstore.doc_get("trips", trip_id)
     if not trip:
         raise HTTPException(404, f"Trip '{trip_id}' not found.")
     tags = [str(t) for t in body.get("available_tags", []) if t]
-    await fstore.doc_update("trips", trip_id, {"available_tags": tags})
-    return {"available_tags": tags}
+    overlap = [str(t) for t in body.get("overlap_tags", []) if t and t in tags]
+    await fstore.doc_update("trips", trip_id, {"available_tags": tags, "overlap_tags": overlap})
+    return {"available_tags": tags, "overlap_tags": overlap}
 
 
 @router.delete("/{trip_id}")
diff --git a/drb-frontend/app/trips/[id]/page.tsx b/drb-frontend/app/trips/[id]/page.tsx
index c246361..c6f7917 100644
--- a/drb-frontend/app/trips/[id]/page.tsx
+++ b/drb-frontend/app/trips/[id]/page.tsx
@@ -86,11 +86,14 @@ function TagPill({ tag, availableTags }: { tag: string; availableTags: string[]
   );
 }
 
-function detectConflicts(events: TripEvent[]): Set<string> {
+function detectConflicts(events: TripEvent[], overlapTags: string[] = []): Set<string> {
   const timed = events.filter((e) => e.start_time);
   const conflicts = new Set<string>();
   for (let i = 0; i < timed.length; i++) {
     for (let j = i + 1; j < timed.length; j++) {
+      const aExempt = timed[i].tags?.some((t) => overlapTags.includes(t));
+      const bExempt = timed[j].tags?.some((t) => overlapTags.includes(t));
+      if (aExempt || bExempt) continue;
       const aS = toMin(timed[i].start_time!);
       const aE = timed[i].end_time ? toMin(timed[i].end_time!) : aS + 60;
       const bS = toMin(timed[j].start_time!);
@@ -365,6 +368,7 @@ function DayTimeline({
   onEdit,
   driveSegments,
   availableTags,
+  overlapTags,
 }: {
   events: TripEvent[];
   isAdmin: boolean;
@@ -372,12 +376,16 @@ function DayTimeline({
   onEdit: (event: TripEvent) => void;
   driveSegments: { fromId: string; toId: string; text: string }[];
   availableTags: string[];
+  overlapTags: string[];
 }) {
   const timed = [...events.filter((e) => e.start_time)].sort(
     (a, b) => toMin(a.start_time!) - toMin(b.start_time!)
   );
   const untimed = events.filter((e) => !e.start_time);
-  const conflicts = detectConflicts(events);
+  const isNote = (e: TripEvent) => !!e.tags?.some((t) => overlapTags.includes(t));
+  const noteEvents    = timed.filter((e) => isNote(e));
+  const regularEvents = timed.filter((e) => !isNote(e));
+  const conflicts = detectConflicts(events, overlapTags);
 
   if (timed.length === 0 && untimed.length === 0) {
     return (
@@ -423,8 +431,45 @@ function DayTimeline({
             </div>
           ))}
 
-          {/* Event blocks */}
-          {timed.map((e) => {
+          {/* Note events — overlap-allowed, rendered behind as subtle bands */}
+          {noteEvents.map((e) => {
+            const startMin = toMin(e.start_time!);
+            const endMin   = e.end_time ? toMin(e.end_time) : startMin;
+            const top      = (startMin - rangeStart) * PX_PER_MIN;
+            const height   = Math.max(1, (endMin - startMin) * PX_PER_MIN);
+
+            return (
+              <div key={e.event_id} className="group">
+                {/* Shaded band (only if duration given) */}
+                {e.end_time && (
+                  <div
+                    style={{ top, height, left: 60, right: 0 }}
+                    className="absolute bg-gray-800/30 border-l-2 border-gray-600/30 z-0 pointer-events-none"
+                  />
+                )}
+                {/* Dashed marker line + label */}
+                <div
+                  style={{ top, left: 60, right: 0 }}
+                  className="absolute z-10 flex items-center gap-2"
+                >
+                  <div className="flex-1 border-t border-dashed border-gray-600/40" />
+                  <span className="text-gray-500 text-[10px] font-mono shrink-0 pr-1">
+                    {fmtTime(e.start_time)}
+                  </span>
+                  <span className="text-gray-500 text-[10px] truncate max-w-[120px] shrink-0">{e.title}</span>
+                  {isAdmin && (
+                    <div className="flex gap-1 opacity-0 group-hover:opacity-100 transition-opacity shrink-0">
+                      <button onClick={() => onEdit(e)} className="text-gray-600 hover:text-indigo-400 text-[10px]">Edit</button>
+                      <button onClick={() => onDelete(e.event_id)} className="text-gray-600 hover:text-red-400 text-xs leading-none">×</button>
+                    </div>
+                  )}
+                </div>
+              </div>
+            );
+          })}
+
+          {/* Regular event blocks */}
+          {regularEvents.map((e) => {
             const startMin  = toMin(e.start_time!);
             const endMin    = e.end_time ? toMin(e.end_time) : startMin + 60;
             const top       = (startMin - rangeStart) * PX_PER_MIN;
@@ -436,7 +481,7 @@ function DayTimeline({
               <div key={e.event_id}>
                 <div
                   style={{ top, height, left: 60, right: 0 }}
-                  className={`absolute rounded-lg px-3 py-2 overflow-hidden group transition-colors ${
+                  className={`absolute rounded-lg px-3 py-2 overflow-hidden group transition-colors z-20 ${
                     isConflict
                       ? "bg-red-950/70 border border-red-700/70"
                       : "bg-indigo-950/60 border border-indigo-800/50 hover:border-indigo-600/70"
@@ -495,11 +540,10 @@ function DayTimeline({
                     </div>
                   </div>
                 </div>
-                {/* Drive time badge below this event, if present */}
                 {drive && (
                   <div
                     style={{ top: top + height + 2, left: 60 }}
-                    className="absolute text-xs text-gray-600 font-mono flex items-center gap-1"
+                    className="absolute text-xs text-gray-600 font-mono flex items-center gap-1 z-20"
                   >
                     <span className="text-gray-700">↓</span> {drive} drive
                   </div>
@@ -965,17 +1009,27 @@ export default function TripDetailPage() {
     if (!trip || !tagInput.trim()) return;
     const tag = tagInput.trim();
     if (trip.available_tags?.includes(tag)) { setTagInput(""); return; }
-    const updated = [...(trip.available_tags ?? []), tag];
-    await c2api.updateTripTags(trip.trip_id, updated);
-    setTrip((prev) => prev ? { ...prev, available_tags: updated } : prev);
+    const available = [...(trip.available_tags ?? []), tag];
+    const overlap = trip.overlap_tags ?? [];
+    await c2api.updateTripTags(trip.trip_id, available, overlap);
+    setTrip((prev) => prev ? { ...prev, available_tags: available } : prev);
     setTagInput("");
   }
 
   async function handleRemoveTag(tag: string) {
     if (!trip) return;
-    const updated = (trip.available_tags ?? []).filter((t) => t !== tag);
-    await c2api.updateTripTags(trip.trip_id, updated);
-    setTrip((prev) => prev ? { ...prev, available_tags: updated } : prev);
+    const available = (trip.available_tags ?? []).filter((t) => t !== tag);
+    const overlap = (trip.overlap_tags ?? []).filter((t) => t !== tag);
+    await c2api.updateTripTags(trip.trip_id, available, overlap);
+    setTrip((prev) => prev ? { ...prev, available_tags: available, overlap_tags: overlap } : prev);
+  }
+
+  async function handleToggleOverlap(tag: string) {
+    if (!trip) return;
+    const current = trip.overlap_tags ?? [];
+    const overlap = current.includes(tag) ? current.filter((t) => t !== tag) : [...current, tag];
+    await c2api.updateTripTags(trip.trip_id, trip.available_tags ?? [], overlap);
+    setTrip((prev) => prev ? { ...prev, overlap_tags: overlap } : prev);
   }
 
   if (loading) return <p className="text-gray-500 text-sm font-mono">Loading…</p>;
@@ -985,7 +1039,7 @@ export default function TripDetailPage() {
   const attendees  = Object.values(trip.attendees ?? {});
   const dayEvents  = trip.events.filter((e) => e.date === selectedDay);
   const hasConflict = (day: string) =>
-    detectConflicts(trip.events.filter((e) => e.date === day)).size > 0;
+    detectConflicts(trip.events.filter((e) => e.date === day), trip.overlap_tags ?? []).size > 0;
 
   return (
     <div className="space-y-6">
@@ -1043,14 +1097,26 @@ export default function TripDetailPage() {
         {/* Tag manager */}
         {(isAdmin || (trip.available_tags ?? []).length > 0) && (
           <div className="flex flex-wrap items-center gap-2">
-            {(trip.available_tags ?? []).map((tag) => (
-              <span key={tag} className={`inline-flex items-center gap-1 text-xs rounded-full px-2.5 py-0.5 border ${tagColor(tag, trip.available_tags ?? [])}`}>
-                {tag}
-                {isAdmin && (
-                  <button onClick={() => handleRemoveTag(tag)} className="hover:text-white transition-colors leading-none">×</button>
-                )}
-              </span>
-            ))}
+            {(trip.available_tags ?? []).map((tag) => {
+              const isOverlap = (trip.overlap_tags ?? []).includes(tag);
+              return (
+                <span key={tag} className={`inline-flex items-center gap-1 text-xs rounded-full px-2.5 py-0.5 border ${tagColor(tag, trip.available_tags ?? [])}`}>
+                  {tag}
+                  {isAdmin && (
+                    <>
+                      <button
+                        onClick={() => handleToggleOverlap(tag)}
+                        title={isOverlap ? "Allows overlap (click to disable)" : "Click to allow overlap"}
+                        className={`leading-none transition-colors ${isOverlap ? "opacity-100" : "opacity-30 hover:opacity-70"}`}
+                      >
+                        ≋
+                      </button>
+                      <button onClick={() => handleRemoveTag(tag)} className="hover:text-white transition-colors leading-none opacity-60 hover:opacity-100">×</button>
+                    </>
+                  )}
+                </span>
+              );
+            })}
             {isAdmin && (
               <div className="flex items-center gap-1">
                 <input
@@ -1114,6 +1180,7 @@ export default function TripDetailPage() {
               onEdit={setEditEvent}
               driveSegments={driveTimes[selectedDay] ?? []}
               availableTags={trip.available_tags ?? []}
+              overlapTags={trip.overlap_tags ?? []}
             />
           </div>
         </div>
diff --git a/drb-frontend/lib/c2api.ts b/drb-frontend/lib/c2api.ts
index e893fe3..808d894 100644
--- a/drb-frontend/lib/c2api.ts
+++ b/drb-frontend/lib/c2api.ts
@@ -142,8 +142,8 @@ export const c2api = {
     request<import("@/lib/types").TripRecord>("/trips", { method: "POST", body: JSON.stringify(body) }),
   deleteTrip: (id: string) =>
     request(`/trips/${id}`, { method: "DELETE" }),
-  updateTripTags: (id: string, available_tags: string[]) =>
-    request<{ available_tags: string[] }>(`/trips/${id}/tags`, { method: "PUT", body: JSON.stringify({ available_tags }) }),
+  updateTripTags: (id: string, available_tags: string[], overlap_tags: string[]) =>
+    request<{ available_tags: string[]; overlap_tags: string[] }>(`/trips/${id}/tags`, { method: "PUT", body: JSON.stringify({ available_tags, overlap_tags }) }),
   createTripEvent: (tripId: string, body: object) =>
     request<import("@/lib/types").TripEvent>(`/trips/${tripId}/events`, { method: "POST", body: JSON.stringify(body) }),
   updateTripEvent: (tripId: string, eventId: string, body: object) =>
diff --git a/drb-frontend/lib/types.ts b/drb-frontend/lib/types.ts
index cd5f716..05241d7 100644
--- a/drb-frontend/lib/types.ts
+++ b/drb-frontend/lib/types.ts
@@ -134,6 +134,7 @@ export interface TripRecord {
   end_date: string;
   attendees: Record<string, string>;
   available_tags: string[];
+  overlap_tags: string[];
   created_at: string;
   events?: TripEvent[];
 }