diff --git a/rugnux/rugnux_cli.cpp b/rugnux/rugnux_cli.cpp
index 5b87e72c..3693c421 100644
--- a/rugnux/rugnux_cli.cpp
+++ b/rugnux/rugnux_cli.cpp
@@ -1742,8 +1742,20 @@ static int RunRugnux(int argc, char **argv) {
     if (result.space_group_number.has_value() && anything_indexed) {
         const gemmi::SpaceGroup *sg = gemmi::find_spacegroup_by_number(
             static_cast<int>(result.space_group_number.value()));
-        std::cout << fmt::format("Space group:     {} (No. {})", sg ? sg->short_name() : "?",
-                                 result.space_group_number.value()) << std::endl;
+        std::string line = fmt::format("Space group:     {} (No. {})", sg ? sg->short_name() : "?",
+                                       result.space_group_number.value());
+        // Name every group the data cannot separate, not just the representative. Some pairs share
+        // their whole absence pattern - an enantiomorphic pair (P4_1 vs P4_3), or I23 vs I2_13 and
+        // I222 vs I2_12_12_1, where the screw condition h00: h=2n is already implied by the
+        // I-centering - so the choice among them is a convention, not a measurement. The search
+        // reports the representative as the lowest space-group number; saying so here keeps the
+        // summary from claiming a decision the diffraction did not make.
+        if (result.space_group_search.has_value())
+            for (const auto &alt : result.space_group_search->alternatives)
+                line += fmt::format(" or {} (No. {})", alt.short_name(), alt.number);
+        if (result.space_group_search.has_value() && !result.space_group_search->alternatives.empty())
+            line += " - indistinguishable from these data";
+        std::cout << line << std::endl;
     }
     if (result.consensus_cell.has_value() && anything_indexed) {
         const auto &c = result.consensus_cell.value();