diff --git a/app.go b/app.go
index 7945997..ec3c0d4 100644
--- a/app.go
+++ b/app.go
@@ -6162,6 +6162,12 @@ var bulkFieldColumns = map[string]string{
 	"iota":     "iota",
 	"sig":      "sig",
 	"sig_info": "sig_info",
+	// The contact itself — repair fields. Setting mode also clears submode, in
+	// qso.BulkSetField: a submode left over from the old mode contradicts the new.
+	"mode":     "mode",
+	"submode":  "submode",
+	"rst_sent": "rst_sent",
+	"rst_rcvd": "rst_rcvd",
 	// Misc text
 	"comment": "comment",
 	"notes":   "notes",
diff --git a/bulkfields_test.go b/bulkfields_test.go
new file mode 100644
index 0000000..7537fac
--- /dev/null
+++ b/bulkfields_test.go
@@ -0,0 +1,35 @@
+package main
+
+import (
+	"testing"
+
+	"hamlog/internal/qso"
+)
+
+// A bulk-editable field passes through THREE tables: the field list in the UI,
+// bulkFieldColumns here, and bulkEditableCols in internal/qso. Mode and RST were
+// added to the first and the third and not the second, so the dialog offered
+// them and the save failed with "unknown field" — reported from the field.
+//
+// Nothing warns about that: each table is valid on its own. This is the check.
+func TestEveryMappedBulkFieldIsWhitelisted(t *testing.T) {
+	for id, col := range bulkFieldColumns {
+		if !qso.BulkEditable(col) {
+			t.Errorf("bulk field %q maps to column %q, which internal/qso refuses to write", id, col)
+		}
+	}
+}
+
+// And the reverse: a column the qso layer allows but nothing maps to is dead
+// weight — it looks supported from the inside and cannot be reached from outside.
+func TestNoUnreachableBulkColumn(t *testing.T) {
+	mapped := map[string]bool{}
+	for _, col := range bulkFieldColumns {
+		mapped[col] = true
+	}
+	for _, col := range qso.BulkEditableColumns() {
+		if !mapped[col] {
+			t.Errorf("column %q is bulk-writable but no field maps to it — unreachable", col)
+		}
+	}
+}
diff --git a/internal/qso/qso.go b/internal/qso/qso.go
index e552db1..9dfe84d 100644
--- a/internal/qso/qso.go
+++ b/internal/qso/qso.go
@@ -896,6 +896,23 @@ var bulkEditableExtras = map[string]string{
 // BulkExtraKey maps a frontend field id to its ADIF key in extras_json, or "".
 func BulkExtraKey(field string) string { return bulkEditableExtras[field] }
 
+// BulkEditable reports whether a COLUMN may be bulk-written. Exported so the
+// app layer can check its own field mapping against this whitelist: the two
+// lists are separate, valid on their own, and a field present in one and absent
+// from the other fails only when an operator tries to use it.
+func BulkEditable(column string) bool { return bulkEditableCols[column] }
+
+// BulkEditableColumns lists every bulk-writable column, for the same check from
+// the other side: a column nothing maps to looks supported and cannot be used.
+func BulkEditableColumns() []string {
+	out := make([]string, 0, len(bulkEditableCols))
+	for c := range bulkEditableCols {
+		out = append(out, c)
+	}
+	sort.Strings(out)
+	return out
+}
+
 // BulkSetExtra sets one whitelisted extras_json field on every listed QSO,
 // leaving the other extras untouched. An empty value REMOVES the key rather than
 // storing a blank — an empty extra would otherwise be carried into every export.