diff --git a/backend/internal/web/admin_series_detail.go b/backend/internal/web/admin_series_detail.go
index 8178aba..4166f9a 100644
--- a/backend/internal/web/admin_series_detail.go
+++ b/backend/internal/web/admin_series_detail.go
@@ -33,6 +33,12 @@ type seriesDetailView struct {
 	// owner's, and it dies with the stamp (a machine write of the number).
 	Corrected string
 
+	// Provenance is the actor class behind the current Chapter: "correction",
+	// "sighting" or "machine read"; "" while the Series was never read, when
+	// the line is not rendered. Derived from the same anonymous stamps the
+	// marks above read — no Reader identity crosses here.
+	Provenance string
+
 	// Marks, one per hygiene fact, rendered only while it holds.
 	Unpollable     bool // no SeriesURL to fetch
 	NoCover        bool
@@ -130,6 +136,24 @@ func (h *Handler) seriesDetailView(a store.AdminSeries) seriesDetailView {
 		v.Checked = since(time.Now(), time.UnixMilli(a.LatestCheckedAt))
 	}
 	v.Corrected = correctedAge(time.Now(), a.LatestCorrectedAt)
+
+	// Provenance: the actor class behind the current number, evaluated in the
+	// order the classes outrank one another — the owner's stamp, which a
+	// Correction leaves standing and a machine write clears (issue #149); a
+	// raising Reader, which a Correction drops; then any check stamp at all.
+	// An Acquisition reads as a machine read because it stamps
+	// latest_checked_at exactly as a Poll does, so the two are
+	// indistinguishable the moment it finishes; telling them apart would need
+	// the column this project declines to add (spec #135), and the one
+	// actionable case — acquired once, never read again — is already the
+	// unchecked filter.
+	if a.LatestCorrectedAt != 0 {
+		v.Provenance = "correction"
+	} else if a.RaisedByReader {
+		v.Provenance = "sighting"
+	} else if a.LatestCheckedAt != 0 {
+		v.Provenance = "machine read"
+	}
 	return v
 }
 
diff --git a/backend/internal/web/admin_series_detail_test.go b/backend/internal/web/admin_series_detail_test.go
new file mode 100644
index 0000000..e244ead
--- /dev/null
+++ b/backend/internal/web/admin_series_detail_test.go
@@ -0,0 +1,34 @@
+package web
+
+import (
+	"testing"
+
+	"bookmarkmanager/backend/internal/store"
+)
+
+// seriesDetailView derives the provenance line from the three stamps the
+// admin projection already carries: the correction stamp outranks a raising
+// Reader, which outranks a check stamp, and a Series with none of the three
+// renders no line at all — it was never read, and no actor class is true of
+// it. Acquisition stamps latest_checked_at exactly as a Poll does, so an
+// acquired value lands in the same "machine read" class (#152).
+func TestSeriesDetailViewProvenance(t *testing.T) {
+	cases := []struct {
+		name string
+		a    store.AdminSeries
+		want string
+	}{
+		{"correction stamp", store.AdminSeries{LatestCorrectedAt: 1}, "correction"},
+		{"raising reader only", store.AdminSeries{RaisedByReader: true}, "sighting"},
+		{"check stamp only", store.AdminSeries{LatestCheckedAt: 1}, "machine read"},
+		{"correction outranks sighting", store.AdminSeries{LatestCorrectedAt: 1, RaisedByReader: true}, "correction"},
+		{"none of the three", store.AdminSeries{}, ""},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := (&Handler{}).seriesDetailView(tc.a).Provenance; got != tc.want {
+				t.Fatalf("Provenance = %q, want %q", got, tc.want)
+			}
+		})
+	}
+}
diff --git a/backend/internal/web/templates/series-detail.html b/backend/internal/web/templates/series-detail.html
index c5a800c..71f63c8 100644
--- a/backend/internal/web/templates/series-detail.html
+++ b/backend/internal/web/templates/series-detail.html
@@ -38,10 +38,13 @@
 
 {{/* series-detail-meta is the meta line, and the answer a Check now or
      correction press on the detail page swaps into its place: the same marks,
-     re-rendered after the stamp so the pending and corrected markers show. */}}
+     re-rendered after the stamp so the pending and corrected markers — and
+     the provenance line beside the number — describe the value they sit
+     next to. */}}
 {{define "series-detail-meta"}}
 <div class="detail-meta" id="detail-meta">
   <span>ch {{.Chapter}}</span>
+  {{if .Provenance}}<span>{{.Provenance}}</span>{{end}}
   <span>checked {{.Checked}}</span>
   <span>{{.Readers}} readers</span>
   {{if .Corrected}}<span class="mark">{{.Corrected}}</span>{{end}}
@@ -51,4 +54,4 @@
   {{if .Orphan}}<span class="mark">orphan</span>{{end}}
   {{if .SightingRaised}}<span class="mark">sighting-raised</span>{{end}}
 </div>
-{{end}}
+{{end}}
\ No newline at end of file
diff --git a/backend/web_test.go b/backend/web_test.go
index 5c048fe..2241186 100644
--- a/backend/web_test.go
+++ b/backend/web_test.go
@@ -2722,6 +2722,60 @@ func TestAdminSeriesDetailRendersMarks(t *testing.T) {
 	}
 }
 
+// The provenance line beside the chapter names the actor class behind the
+// value — "machine read" for a checked Series, "correction" for the owner's
+// stamp, "sighting" for a Reader-raised one — and appears nowhere in the
+// rendered Series list: an actor class is context for the Series the owner is
+// already looking at, never a population to sweep (#152).
+func TestAdminSeriesDetailProvenanceLine(t *testing.T) {
+	router, st := newWebTestServer(t, testConfig())
+
+	seed(t, st, store.Bookmark{
+		Key: "asura:machine", Site: "asura", SeriesID: "machine",
+		Title: "Machine", SeriesURL: "https://asurascans.com/series/machine",
+		Kind: "manga", LatestChapter: "45", LatestChapterNum: floatPtr(45),
+	})
+	if err := st.MarkLatestChecked("asura", "machine", time.Now().Add(-time.Hour).UnixMilli()); err != nil {
+		t.Fatalf("MarkLatestChecked: %v", err)
+	}
+
+	seed(t, st, store.Bookmark{
+		Key: "asura:hand", Site: "asura", SeriesID: "hand",
+		Title: "Hand", SeriesURL: "https://asurascans.com/series/hand",
+		Kind: "manga", LatestChapter: "12", LatestChapterNum: floatPtr(12),
+	})
+	if err := st.CorrectLatestChapter("asura", "hand", 13, time.Now().UnixMilli()); err != nil {
+		t.Fatalf("CorrectLatestChapter: %v", err)
+	}
+
+	seed(t, st, store.Bookmark{
+		Key: "demonic:raised", Site: "demonic", SeriesID: "raised",
+		Title: "Raised", SeriesURL: "https://demonicscans.org/series/raised",
+		Kind: "manga",
+	})
+	if err := st.RecordSighting(st.OwnerID(), "demonic", "raised", floatPtr(7), time.Now().UnixMilli()); err != nil {
+		t.Fatalf("RecordSighting: %v", err)
+	}
+
+	for _, tc := range []struct{ key, want string }{
+		{"asura:machine", "machine read"},
+		{"asura:hand", "correction"},
+		{"demonic:raised", "sighting"},
+	} {
+		body := seriesDetailPage(t, router, st, tc.key)
+		if !strings.Contains(body, "<span>"+tc.want+"</span>") {
+			t.Errorf("detail %s lacks the %q provenance line:\n%s", tc.key, tc.want, body)
+		}
+	}
+
+	listBody := adminSeriesPage(t, router, st, "")
+	for _, word := range []string{"machine read", "correction", "sighting"} {
+		if strings.Contains(listBody, "<span>"+word+"</span>") {
+			t.Errorf("Series list carries a %q provenance line:\n%s", word, listBody)
+		}
+	}
+}
+
 // A well-formed key naming no row is a 404, and so is a key with no ":",
 // an empty Site or an empty SeriesID — the detail page never answers 500 for
 // an address nobody can reach.