diff --git a/src/db/db/db.pro b/src/db/db/db.pro
index 770575fd7..ea36ff395 100644
--- a/src/db/db/db.pro
+++ b/src/db/db/db.pro
@@ -183,7 +183,8 @@ SOURCES = \
     dbLayoutVsSchematicFormatDefs.cc \
     dbLayoutVsSchematic.cc \
     gsiDeclDbNetlistCrossReference.cc \
-    gsiDeclDbLayoutVsSchematic.cc
+    gsiDeclDbLayoutVsSchematic.cc \
+    dbNetlistObject.cc
 
 HEADERS = \
   dbArray.h \
@@ -329,7 +330,8 @@ HEADERS = \
     dbLayoutVsSchematicWriter.h \
     dbLayoutVsSchematicReader.h \
     dbLayoutVsSchematicFormatDefs.h \
-    dbLayoutVsSchematic.h
+    dbLayoutVsSchematic.h \
+    dbNetlistObject.h
 
 !equals(HAVE_QT, "0") {
 
diff --git a/src/db/db/dbCircuit.cc b/src/db/db/dbCircuit.cc
index f608a9f77..1ca2d79c7 100644
--- a/src/db/db/dbCircuit.cc
+++ b/src/db/db/dbCircuit.cc
@@ -33,7 +33,7 @@ namespace db
 //  Circuit class implementation
 
 Circuit::Circuit ()
-  : m_dont_purge (false), m_cell_index (0), mp_netlist (0),
+  : db::NetlistObject (), gsi::ObjectBase (), m_dont_purge (false), m_cell_index (0), mp_netlist (0),
     m_device_by_id (this, &Circuit::begin_devices, &Circuit::end_devices),
     m_subcircuit_by_id (this, &Circuit::begin_subcircuits, &Circuit::end_subcircuits),
     m_net_by_cluster_id (this, &Circuit::begin_nets, &Circuit::end_nets),
@@ -48,7 +48,7 @@ Circuit::Circuit ()
 }
 
 Circuit::Circuit (const db::Layout &layout, db::cell_index_type ci)
-  : m_name (layout.cell_name (ci)), m_dont_purge (false), m_cell_index (ci), mp_netlist (0),
+  : db::NetlistObject (), gsi::ObjectBase (), m_name (layout.cell_name (ci)), m_dont_purge (false), m_cell_index (ci), mp_netlist (0),
     m_device_by_id (this, &Circuit::begin_devices, &Circuit::end_devices),
     m_subcircuit_by_id (this, &Circuit::begin_subcircuits, &Circuit::end_subcircuits),
     m_net_by_cluster_id (this, &Circuit::begin_nets, &Circuit::end_nets),
@@ -65,7 +65,7 @@ Circuit::Circuit (const db::Layout &layout, db::cell_index_type ci)
 }
 
 Circuit::Circuit (const Circuit &other)
-  : gsi::ObjectBase (other), tl::Object (other), m_dont_purge (false), m_cell_index (0), mp_netlist (0),
+  : db::NetlistObject (other), gsi::ObjectBase (other), m_dont_purge (false), m_cell_index (0), mp_netlist (0),
     m_device_by_id (this, &Circuit::begin_devices, &Circuit::end_devices),
     m_subcircuit_by_id (this, &Circuit::begin_subcircuits, &Circuit::end_subcircuits),
     m_net_by_cluster_id (this, &Circuit::begin_nets, &Circuit::end_nets),
@@ -95,6 +95,8 @@ Circuit &Circuit::operator= (const Circuit &other)
 {
   if (this != &other) {
 
+    db::NetlistObject::operator= (other);
+
     clear ();
 
     m_name = other.m_name;
@@ -290,6 +292,13 @@ void Circuit::clear_pins ()
   m_pins.clear ();
 }
 
+const Pin &Circuit::add_pin (const Pin &pin)
+{
+  m_pins.push_back (pin);
+  m_pins.back ().set_id (m_pins.size () - 1);
+  return m_pins.back ();
+}
+
 const Pin &Circuit::add_pin (const std::string &name)
 {
   m_pins.push_back (Pin (name));
diff --git a/src/db/db/dbCircuit.h b/src/db/db/dbCircuit.h
index 3092fb6cd..c8bcac695 100644
--- a/src/db/db/dbCircuit.h
+++ b/src/db/db/dbCircuit.h
@@ -86,7 +86,7 @@ public:
  *  devices.
  */
 class DB_PUBLIC Circuit
-  : public gsi::ObjectBase, public tl::Object
+  : public db::NetlistObject, public gsi::ObjectBase
 {
 public:
   typedef tl::vector<Pin> pin_list;
@@ -324,6 +324,12 @@ public:
    */
   const Pin &add_pin (const std::string &name);
 
+  /**
+   *  @brief Adds a pin to this circuit
+   *  This version uses the given pin as the template.
+   */
+  const Pin &add_pin (const Pin &pin);
+
   /**
    *  @brief Begin iterator for the pins of the circuit (non-const version)
    */
@@ -353,6 +359,14 @@ public:
    */
   const Pin *pin_by_id (size_t id) const;
 
+  /**
+   *  @brief Gets the pin by ID (the ID is basically the index) - non-const version
+   */
+  Pin *pin_by_id (size_t id)
+  {
+    return const_cast<Pin *> (((const db::Circuit *) this)->pin_by_id (id));
+  }
+
   /**
    *  @brief Gets the pin by name
    *
@@ -361,6 +375,14 @@ public:
    */
   const Pin *pin_by_name (const std::string &name) const;
 
+  /**
+   *  @brief Gets the pin by name - non-const version
+   */
+  Pin *pin_by_name (const std::string &name)
+  {
+    return const_cast<Pin *> (((const db::Circuit *) this)->pin_by_name (name));
+  }
+
   /**
    *  @brief Begin iterator for the pins of the circuit (const version)
    */
diff --git a/src/db/db/dbDevice.cc b/src/db/db/dbDevice.cc
index ca950ad2e..a1c0dbf34 100644
--- a/src/db/db/dbDevice.cc
+++ b/src/db/db/dbDevice.cc
@@ -31,7 +31,7 @@ namespace db
 //  Device class implementation
 
 Device::Device ()
-  : mp_device_class (0), mp_device_abstract (0), m_id (0), mp_circuit (0)
+  : db::NetlistObject (), mp_device_class (0), mp_device_abstract (0), m_id (0), mp_circuit (0)
 {
   //  .. nothing yet ..
 }
@@ -46,19 +46,19 @@ Device::~Device ()
 }
 
 Device::Device (DeviceClass *device_class, const std::string &name)
-  : mp_device_class (device_class), mp_device_abstract (0), m_name (name), m_id (0), mp_circuit (0)
+  : db::NetlistObject (), mp_device_class (device_class), mp_device_abstract (0), m_name (name), m_id (0), mp_circuit (0)
 {
   //  .. nothing yet ..
 }
 
 Device::Device (DeviceClass *device_class, DeviceAbstract *device_abstract, const std::string &name)
-  : mp_device_class (device_class), mp_device_abstract (device_abstract), m_name (name), m_id (0), mp_circuit (0)
+  : db::NetlistObject (), mp_device_class (device_class), mp_device_abstract (device_abstract), m_name (name), m_id (0), mp_circuit (0)
 {
   //  .. nothing yet ..
 }
 
 Device::Device (const Device &other)
-  : tl::Object (other), mp_device_class (0), mp_device_abstract (0), m_id (0), mp_circuit (0)
+  : db::NetlistObject (other), mp_device_class (0), mp_device_abstract (0), m_id (0), mp_circuit (0)
 {
   operator= (other);
 }
@@ -66,6 +66,7 @@ Device::Device (const Device &other)
 Device &Device::operator= (const Device &other)
 {
   if (this != &other) {
+    db::NetlistObject::operator= (other);
     m_name = other.m_name;
     m_trans = other.m_trans;
     m_parameters = other.m_parameters;
diff --git a/src/db/db/dbDevice.h b/src/db/db/dbDevice.h
index 7e6b8af3e..f93058369 100644
--- a/src/db/db/dbDevice.h
+++ b/src/db/db/dbDevice.h
@@ -95,7 +95,7 @@ struct DeviceAbstractRef
  *  a specific device class.
  */
 class DB_PUBLIC Device
-  : public tl::Object
+  : public db::NetlistObject
 {
 public:
   typedef std::vector<std::pair<size_t, size_t> > global_connections;
diff --git a/src/db/db/dbLayoutToNetlist.cc b/src/db/db/dbLayoutToNetlist.cc
index b30dfb26a..f33bd4286 100644
--- a/src/db/db/dbLayoutToNetlist.cc
+++ b/src/db/db/dbLayoutToNetlist.cc
@@ -814,11 +814,20 @@ LayoutToNetlist::build_net_rec (db::cell_index_type ci, size_t cid, db::Layout &
 db::properties_id_type
 LayoutToNetlist::make_netname_propid (db::Layout &ly, const tl::Variant &netname_prop, const db::Net &net) const
 {
-  if (! netname_prop.is_nil ()) {
+  if (! netname_prop.is_nil () || net.begin_properties () != net.end_properties ()) {
 
-    db::property_names_id_type name_propnameid = ly.properties_repository ().prop_name_id (netname_prop);
     db::PropertiesRepository::properties_set propset;
-    propset.insert (std::make_pair (name_propnameid, tl::Variant (net.expanded_name ())));
+
+    //  add the user properties too (TODO: make this configurable?)
+    for (db::Net::property_iterator p = net.begin_properties (); p != net.end_properties (); ++p) {
+      db::property_names_id_type key_propnameid = ly.properties_repository ().prop_name_id (p->first);
+      propset.insert (std::make_pair (key_propnameid, p->second));
+    }
+
+    if (! netname_prop.is_nil ()) {
+      db::property_names_id_type name_propnameid = ly.properties_repository ().prop_name_id (netname_prop);
+      propset.insert (std::make_pair (name_propnameid, tl::Variant (net.expanded_name ())));
+    }
 
     return ly.properties_repository ().properties_id (propset);
 
diff --git a/src/db/db/dbLayoutToNetlistFormatDefs.cc b/src/db/db/dbLayoutToNetlistFormatDefs.cc
index eabcaa83a..ce6532619 100644
--- a/src/db/db/dbLayoutToNetlistFormatDefs.cc
+++ b/src/db/db/dbLayoutToNetlistFormatDefs.cc
@@ -43,6 +43,7 @@ namespace l2n_std_format
   DB_PUBLIC std::string LongKeys::circuit_key ("circuit");
   DB_PUBLIC std::string LongKeys::net_key ("net");
   DB_PUBLIC std::string LongKeys::name_key ("name");
+  DB_PUBLIC std::string LongKeys::property_key ("property");
   DB_PUBLIC std::string LongKeys::device_key ("device");
   DB_PUBLIC std::string LongKeys::polygon_key ("polygon");
   DB_PUBLIC std::string LongKeys::rect_key ("rect");
@@ -55,7 +56,7 @@ namespace l2n_std_format
   DB_PUBLIC std::string LongKeys::scale_key ("scale");
   DB_PUBLIC std::string LongKeys::pin_key ("pin");
 
-  //  A, B, C, D, E, G, I, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y
+  //  A, B, C, D, E, F, G, I, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y
   DB_PUBLIC std::string ShortKeys::version_key ("V");
   DB_PUBLIC std::string ShortKeys::description_key ("B");
   DB_PUBLIC std::string ShortKeys::top_key ("W");
@@ -67,6 +68,7 @@ namespace l2n_std_format
   DB_PUBLIC std::string ShortKeys::circuit_key ("X");
   DB_PUBLIC std::string ShortKeys::net_key ("N");
   DB_PUBLIC std::string ShortKeys::name_key ("I");
+  DB_PUBLIC std::string ShortKeys::property_key ("F");
   DB_PUBLIC std::string ShortKeys::device_key ("D");
   DB_PUBLIC std::string ShortKeys::polygon_key ("Q");
   DB_PUBLIC std::string ShortKeys::rect_key ("R");
diff --git a/src/db/db/dbLayoutToNetlistFormatDefs.h b/src/db/db/dbLayoutToNetlistFormatDefs.h
index 8d70abcbc..f0b595290 100644
--- a/src/db/db/dbLayoutToNetlistFormatDefs.h
+++ b/src/db/db/dbLayoutToNetlistFormatDefs.h
@@ -66,7 +66,9 @@ namespace db
  *
  *    [boundary-def]
  *
- *    net(<id> [name]? [geometry-def]*)
+ *    [property-def]*
+ *
+ *    net(<id> [name]? [property-def]* [geometry-def]*)
  *                                  - net geometry [short key: N]
  *                                    A net declaration shall be there also if no geometry
  *                                    is present. The ID is a numerical shortcut for the net.
@@ -103,6 +105,14 @@ namespace db
  *
  *    name(<name>)                  - specify net name [short key: I]
  *
+ *  [property-def]:
+ *
+ *    property(<prop-name> <prop-value>)
+ *                                  - specifies a property value/key pair [short key: F]
+ *                                    prop-name and prop-value are variant specifications
+ *                                    in klayout notation: #x is an integer, ##y a floating-point
+ *                                    value, a word or quoted literal is a string.
+ *
  *  [geometry-def]:
  *
  *    polygon(<layer> [coord] ...)  - defines a polygon [short key: Q]
@@ -123,24 +133,26 @@ namespace db
  *
  *  [device-def]:
  *
- *    [trans-def]                   - location of the device [short key Y]
+ *    [property-def]*               - user properties
+ *    [trans-def]                   - location of the device
  *                                    must be before terminal
- *    param(<name> <value>)         - defines a parameter [short key E]
+ *    param(<name> <value>)         - defines a parameter [short key: E]
  *    terminal(<terminal-name> <net-id>)
  *                                  - specifies connection of the terminal with
  *                                    a net (short key: T)
  *
  *  [subcircuit-def]:
  *
- *    [trans-def]                   - location of the subcircuit [short key Y]
+ *    [property-def]*               - user properties
+ *    [trans-def]                   - location of the subcircuit
  *    pin(<pin-id> <net-id>)        - specifies connection of the pin with a net [short key: P]
  *
  *  [trans-def]:
  *
- *    location(<x> <y>)             - location of the instance [short key Y]
- *    rotation(<angle>)             - rotation angle (in degree, default is 0) [short key O]
- *    mirror                        - if specified, the instance is mirrored before rotation [short key M]
- *    scale(<mag>)                  - magnification (default is 1) [short key S]
+ *    location(<x> <y>)             - location of the instance [short key: Y]
+ *    rotation(<angle>)             - rotation angle (in degree, default is 0) [short key: O]
+ *    mirror                        - if specified, the instance is mirrored before rotation [short key: M]
+ *    scale(<mag>)                  - magnification (default is 1) [short key: S]
  */
 
 namespace l2n_std_format
@@ -160,6 +172,7 @@ namespace l2n_std_format
     static std::string circuit_key;
     static std::string net_key;
     static std::string name_key;
+    static std::string property_key;
     static std::string device_key;
     static std::string subcircuit_key;
     static std::string polygon_key;
@@ -191,6 +204,7 @@ namespace l2n_std_format
     static std::string circuit_key;
     static std::string net_key;
     static std::string name_key;
+    static std::string property_key;
     static std::string device_key;
     static std::string subcircuit_key;
     static std::string polygon_key;
diff --git a/src/db/db/dbLayoutToNetlistReader.cc b/src/db/db/dbLayoutToNetlistReader.cc
index 5cfa6ac49..0c073aaf6 100644
--- a/src/db/db/dbLayoutToNetlistReader.cc
+++ b/src/db/db/dbLayoutToNetlistReader.cc
@@ -305,7 +305,9 @@ void LayoutToNetlistStandardReader::read_netlist (db::Netlist *netlist, db::Layo
 
       while (br) {
 
-        if (test (skeys::rect_key) || test (lkeys::rect_key)) {
+        if (test (skeys::property_key) || test (lkeys::property_key)) {
+          read_property (circuit);
+        } else if (test (skeys::rect_key) || test (lkeys::rect_key)) {
           circuit->set_boundary (db::DPolygon (dbu * read_rect ()));
         } else if (test (skeys::polygon_key) || test (lkeys::polygon_key)) {
           circuit->set_boundary (read_polygon ().transformed (dbu));
@@ -423,6 +425,22 @@ LayoutToNetlistStandardReader::read_point ()
   return m_ref;
 }
 
+void
+LayoutToNetlistStandardReader::read_property (db::NetlistObject *obj)
+{
+  Brace br (this);
+
+  tl::Variant k, v;
+  m_ex.read (k);
+  m_ex.read (v);
+
+  if (obj) {
+    obj->set_property (k, v);
+  }
+
+  br.done ();
+}
+
 std::pair<unsigned int, db::PolygonRef>
 LayoutToNetlistStandardReader::read_geometry (db::LayoutToNetlist *l2n)
 {
@@ -502,14 +520,18 @@ LayoutToNetlistStandardReader::read_polygon ()
 }
 
 void
-LayoutToNetlistStandardReader::read_geometries (Brace &br, db::LayoutToNetlist *l2n, db::local_cluster<db::PolygonRef> &lc, db::Cell &cell)
+LayoutToNetlistStandardReader::read_geometries (db::NetlistObject *obj, Brace &br, db::LayoutToNetlist *l2n, db::local_cluster<db::PolygonRef> &lc, db::Cell &cell)
 {
   m_ref = db::Point ();
 
   while (br) {
-    std::pair<unsigned int, db::PolygonRef> pr = read_geometry (l2n);
-    lc.add (pr.second, pr.first);
-    cell.shapes (pr.first).insert (pr.second);
+    if (test (skeys::property_key) || test (lkeys::property_key)) {
+      read_property (obj);
+    } else {
+      std::pair<unsigned int, db::PolygonRef> pr = read_geometry (l2n);
+      lc.add (pr.second, pr.first);
+      cell.shapes (pr.first).insert (pr.second);
+    }
   }
 }
 
@@ -540,7 +562,7 @@ LayoutToNetlistStandardReader::read_net (db::Netlist * /*netlist*/, db::LayoutTo
     net->set_cluster_id (lc.id ());
 
     db::Cell &cell = l2n->internal_layout ()->cell (circuit->cell_index ());
-    read_geometries (br, l2n, lc, cell);
+    read_geometries (net, br, l2n, lc, cell);
 
   }
 
@@ -552,21 +574,28 @@ LayoutToNetlistStandardReader::read_pin (db::Netlist * /*netlist*/, db::LayoutTo
 {
   Brace br (this);
 
-  std::string name;
   db::Net *net = 0;
 
+  db::Pin pin;
+
   while (br) {
 
     if (test (skeys::name_key) || test (lkeys::name_key)) {
 
-      if (!name.empty ()) {
+      if (! pin.name ().empty ()) {
         throw tl::Exception (tl::to_string (tr ("Duplicate pin name")));
       }
 
       Brace br_name (this);
-      read_word_or_quoted (name);
+      std::string n;
+      read_word_or_quoted (n);
+      pin.set_name (n);
       br_name.done ();
 
+    } else if (test (skeys::property_key) || test (lkeys::property_key)) {
+
+      read_property (&pin);
+
     } else {
 
       if (net) {
@@ -583,9 +612,9 @@ LayoutToNetlistStandardReader::read_pin (db::Netlist * /*netlist*/, db::LayoutTo
 
   }
 
-  const db::Pin &pin = circuit->add_pin (name);
+  size_t pin_id = circuit->add_pin (pin).id ();
   if (net) {
-    circuit->connect_pin (pin.id (), net);
+    circuit->connect_pin (pin_id, net);
   }
 
   br.done ();
@@ -657,6 +686,10 @@ LayoutToNetlistStandardReader::read_device (db::Netlist *netlist, db::LayoutToNe
 
       //  .. nothing yet ..
 
+    } else if (test (skeys::property_key) || test (lkeys::property_key)) {
+
+      read_property (device.get ());
+
     } else if (test (skeys::device_key) || test (lkeys::device_key)) {
 
       std::string n;
@@ -900,6 +933,10 @@ LayoutToNetlistStandardReader::read_subcircuit (db::Netlist *netlist, db::Layout
 
       //  .. nothing yet ..
 
+    } else if (test (skeys::property_key) || test (lkeys::property_key)) {
+
+      read_property (subcircuit.get ());
+
     } else if (test (skeys::pin_key) || test (lkeys::pin_key)) {
 
       Brace br2 (this);
@@ -989,7 +1026,7 @@ LayoutToNetlistStandardReader::read_abstract_terminal (db::LayoutToNetlist *l2n,
     dm->set_cluster_id_for_terminal (tid, lc.id ());
 
     db::Cell &cell = l2n->internal_layout ()->cell (dm->cell_index ());
-    read_geometries (br, l2n, lc, cell);
+    read_geometries (0, br, l2n, lc, cell);
 
   }
 
diff --git a/src/db/db/dbLayoutToNetlistReader.h b/src/db/db/dbLayoutToNetlistReader.h
index 5d256c84e..db2c9d665 100644
--- a/src/db/db/dbLayoutToNetlistReader.h
+++ b/src/db/db/dbLayoutToNetlistReader.h
@@ -140,9 +140,10 @@ protected:
   bool read_trans_part (db::DCplxTrans &tr);
   void read_abstract_terminal (db::LayoutToNetlist *l2n, db::DeviceAbstract *dm, db::DeviceClass *dc);
   std::pair<unsigned int, db::PolygonRef> read_geometry (db::LayoutToNetlist *l2n);
+  void read_property (db::NetlistObject *obj);
   db::Polygon read_polygon ();
   db::Box read_rect ();
-  void read_geometries (Brace &br, db::LayoutToNetlist *l2n, db::local_cluster<db::PolygonRef> &lc, db::Cell &cell);
+  void read_geometries (db::NetlistObject *obj, Brace &br, db::LayoutToNetlist *l2n, db::local_cluster<db::PolygonRef> &lc, db::Cell &cell);
   db::Point read_point ();
 
 private:
diff --git a/src/db/db/dbLayoutToNetlistWriter.cc b/src/db/db/dbLayoutToNetlistWriter.cc
index b36eaf9ba..fad0c3a9f 100644
--- a/src/db/db/dbLayoutToNetlistWriter.cc
+++ b/src/db/db/dbLayoutToNetlistWriter.cc
@@ -278,6 +278,13 @@ void std_writer_impl<Keys>::write (const db::Netlist *netlist, const db::LayoutT
 
   }
 
+  for (db::NetlistObject::property_iterator p = circuit.begin_properties (); p != circuit.end_properties (); ++p) {
+    if (p == circuit.begin_properties() && ! Keys::is_short ()) {
+      *mp_stream << endl << indent << indent1 << "# Properties" << endl;
+    }
+    *mp_stream << indent << indent1 << Keys::property_key << "(" << p->first.to_parsable_string () << " " << p->second.to_parsable_string () << ")" << endl;
+  }
+
   std::map<const db::Net *, unsigned int> net2id_local;
   std::map<const db::Net *, unsigned int> *net2id = &net2id_local;
   if (net2id_per_circuit) {
@@ -416,12 +423,19 @@ void std_writer_impl<Keys>::write (const db::Netlist *netlist, const db::LayoutT
         } else {
 
           if (! any) {
+
             *mp_stream << indent << indent1 << Keys::net_key << "(" << id;
             if (! net.name ().empty ()) {
               *mp_stream << " " << Keys::name_key << "(" << tl::to_word_or_quoted_string (net.name ()) << ")";
             }
             *mp_stream << endl;
+
+            for (db::NetlistObject::property_iterator p = net.begin_properties (); p != net.end_properties (); ++p) {
+              *mp_stream << indent << indent2 << Keys::property_key << "(" << p->first.to_parsable_string () << " " << p->second.to_parsable_string () << ")" << endl;
+            }
+
             any = true;
+
           }
 
           *mp_stream << indent << indent2;
@@ -449,7 +463,15 @@ void std_writer_impl<Keys>::write (const db::Netlist *netlist, const db::LayoutT
     if (! net.name ().empty ()) {
       *mp_stream << " " << Keys::name_key << "(" << tl::to_word_or_quoted_string (net.name ()) << ")";
     }
-    *mp_stream << ")" << endl;
+    if (net.begin_properties () != net.end_properties ()) {
+      *mp_stream << endl;
+      for (db::NetlistObject::property_iterator p = net.begin_properties (); p != net.end_properties (); ++p) {
+        *mp_stream << indent << indent2 << Keys::property_key << "(" << p->first.to_parsable_string () << " " << p->second.to_parsable_string () << ")" << endl;
+      }
+      *mp_stream << indent << ")" << endl;
+    } else {
+      *mp_stream << ")" << endl;
+    }
 
   }
 }
@@ -470,12 +492,16 @@ void std_writer_impl<Keys>::write (const db::LayoutToNetlist *l2n, const db::Sub
   }
 
   //  each pin in one line for more than a few pins
-  bool separate_lines = (subcircuit.circuit_ref ()->pin_count () > 1);
+  bool separate_lines = (subcircuit.circuit_ref ()->pin_count () > 1) || subcircuit.begin_properties () != subcircuit.end_properties ();
 
   if (separate_lines) {
     *mp_stream << endl;
   }
 
+  for (db::NetlistObject::property_iterator p = subcircuit.begin_properties (); p != subcircuit.end_properties (); ++p) {
+    *mp_stream << indent << indent2 << Keys::property_key << "(" << p->first.to_parsable_string () << " " << p->second.to_parsable_string () << ")" << endl;
+  }
+
   for (db::Circuit::const_pin_iterator p = subcircuit.circuit_ref ()->begin_pins (); p != subcircuit.circuit_ref ()->end_pins (); ++p) {
     const db::Net *net = subcircuit.net_for_pin (p->id ());
     if (net) {
@@ -614,6 +640,10 @@ void std_writer_impl<Keys>::write (const db::LayoutToNetlist * /*l2n*/, const db
     *mp_stream << indent << indent2 << Keys::name_key << "(" << tl::to_word_or_quoted_string (device.name ()) << ")" << endl;
   }
 
+  for (db::NetlistObject::property_iterator p = device.begin_properties (); p != device.end_properties (); ++p) {
+    *mp_stream << indent << indent2 << Keys::property_key << "(" << p->first.to_parsable_string () << " " << p->second.to_parsable_string () << ")" << endl;
+  }
+
   for (std::vector<DeviceParameterDefinition>::const_iterator i = pd.begin (); i != pd.end (); ++i) {
     *mp_stream << indent << indent2 << Keys::param_key << "(" << tl::to_word_or_quoted_string (i->name ()) << " " << tl::sprintf ("%.12g", device.parameter_value (i->id ())) << ")" << endl;
   }
diff --git a/src/db/db/dbNet.cc b/src/db/db/dbNet.cc
index 69f085817..b4e14b59d 100644
--- a/src/db/db/dbNet.cc
+++ b/src/db/db/dbNet.cc
@@ -155,19 +155,19 @@ const Pin *NetSubcircuitPinRef::pin () const
 //  Net class implementation
 
 Net::Net ()
-  : m_cluster_id (0), mp_circuit (0)
+  : NetlistObject (), m_cluster_id (0), mp_circuit (0)
 {
   //  .. nothing yet ..
 }
 
 Net::Net (const std::string &name)
-  : m_cluster_id (0), mp_circuit (0)
+  : NetlistObject (), m_cluster_id (0), mp_circuit (0)
 {
   m_name = name;
 }
 
 Net::Net (const Net &other)
-  : tl::Object (other), m_cluster_id (0), mp_circuit (0)
+  : NetlistObject (other), m_cluster_id (0), mp_circuit (0)
 {
   operator= (other);
 }
@@ -176,6 +176,8 @@ Net &Net::operator= (const Net &other)
 {
   if (this != &other) {
 
+    db::NetlistObject::operator= (other);
+
     clear ();
 
     m_name = other.m_name;
diff --git a/src/db/db/dbNet.h b/src/db/db/dbNet.h
index 25e19324f..532b2f9a3 100644
--- a/src/db/db/dbNet.h
+++ b/src/db/db/dbNet.h
@@ -24,6 +24,7 @@
 #define _HDR_dbNet
 
 #include "dbCommon.h"
+#include "dbNetlistObject.h"
 
 #include "tlObject.h"
 
@@ -360,7 +361,7 @@ private:
  *  A net connects terminals of devices and pins or circuits
  */
 class DB_PUBLIC Net
-  : public tl::Object
+  : public db::NetlistObject
 {
 public:
   typedef std::list<NetTerminalRef> terminal_list;
diff --git a/src/db/db/dbNetlistObject.cc b/src/db/db/dbNetlistObject.cc
new file mode 100644
index 000000000..522417b0d
--- /dev/null
+++ b/src/db/db/dbNetlistObject.cc
@@ -0,0 +1,114 @@
+
+/*
+
+  KLayout Layout Viewer
+  Copyright (C) 2006-2019 Matthias Koefferlein
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+*/
+
+#include "dbNetlistObject.h"
+
+namespace db
+{
+
+NetlistObject::NetlistObject ()
+  : tl::Object (), mp_properties (0)
+{
+  //  .. nothing yet ..
+}
+
+NetlistObject::NetlistObject (const db::NetlistObject &other)
+  : tl::Object (other), mp_properties (0)
+{
+  if (other.mp_properties) {
+    mp_properties = new std::map<tl::Variant, tl::Variant> (*other.mp_properties);
+  }
+}
+
+NetlistObject::~NetlistObject ()
+{
+  delete mp_properties;
+  mp_properties = 0;
+}
+
+NetlistObject &NetlistObject::operator= (const NetlistObject &other)
+{
+  if (this != &other) {
+
+    tl::Object::operator= (other);
+
+    delete mp_properties;
+    mp_properties = 0;
+
+    if (other.mp_properties) {
+      mp_properties = new std::map<tl::Variant, tl::Variant> (*other.mp_properties);
+    }
+
+  }
+  return *this;
+}
+
+tl::Variant NetlistObject::property (const tl::Variant &key) const
+{
+  if (! mp_properties) {
+    return tl::Variant ();
+  }
+
+  std::map<tl::Variant, tl::Variant>::const_iterator i = mp_properties->find (key);
+  if (i == mp_properties->end ()) {
+    return tl::Variant ();
+  } else {
+    return i->second;
+  }
+}
+
+void
+NetlistObject::set_property (const tl::Variant &key, const tl::Variant &value)
+{
+  if (value.is_nil ()) {
+
+    if (mp_properties) {
+      mp_properties->erase (key);
+      if (mp_properties->empty ()) {
+        delete mp_properties;
+        mp_properties = 0;
+      }
+    }
+
+  } else {
+    if (! mp_properties) {
+      mp_properties = new std::map<tl::Variant, tl::Variant> ();
+    }
+    (*mp_properties) [key] = value;
+  }
+}
+
+static NetlistObject::property_table empty_properties;
+
+NetlistObject::property_iterator
+NetlistObject::begin_properties () const
+{
+  return mp_properties ? mp_properties->begin () : empty_properties.begin ();
+}
+
+NetlistObject::property_iterator
+NetlistObject::end_properties () const
+{
+  return mp_properties ? mp_properties->end () : empty_properties.end ();
+}
+
+}
diff --git a/src/db/db/dbNetlistObject.h b/src/db/db/dbNetlistObject.h
new file mode 100644
index 000000000..d1dac4891
--- /dev/null
+++ b/src/db/db/dbNetlistObject.h
@@ -0,0 +1,94 @@
+
+/*
+
+  KLayout Layout Viewer
+  Copyright (C) 2006-2019 Matthias Koefferlein
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+*/
+
+#ifndef _HDR_dbNetlistObject
+#define _HDR_dbNetlistObject
+
+#include "dbCommon.h"
+#include "tlObject.h"
+#include "tlVariant.h"
+
+#include <list>
+#include <string>
+
+namespace db
+{
+
+/**
+ *  @brief A base class for a objects in the netlist
+ */
+class DB_PUBLIC NetlistObject
+  : public tl::Object
+{
+public:
+  typedef std::map<tl::Variant, tl::Variant> property_table;
+  typedef property_table::const_iterator property_iterator;
+
+  /**
+   *  @brief Default constructor
+   */
+  NetlistObject ();
+
+  /**
+   *  @brief Copy constructor
+   */
+  NetlistObject (const db::NetlistObject &object);
+
+  /**
+   *  @brief Destructor
+   */
+  ~NetlistObject ();
+
+  /**
+   *  @brief Assignment
+   */
+  NetlistObject &operator= (const NetlistObject &other);
+
+  /**
+   *  @brief Gets the property value for a given key
+   *  Returns nil if there is no property for the given key.
+   */
+  tl::Variant property (const tl::Variant &key) const;
+
+  /**
+   *  @brief Sets the property value for a given key
+   *  Set the value to nil to clear a specific key
+   */
+  void set_property (const tl::Variant &key, const tl::Variant &value);
+
+  /**
+   *  @brief Iterator for the netlist properties (begin)
+   */
+  property_iterator begin_properties () const;
+
+  /**
+   *  @brief Iterator for the netlist properties (end)
+   */
+  property_iterator end_properties () const;
+
+private:
+  property_table *mp_properties;
+};
+
+}
+
+#endif
diff --git a/src/db/db/dbPin.cc b/src/db/db/dbPin.cc
index e223ec8ae..0e1a0e3d8 100644
--- a/src/db/db/dbPin.cc
+++ b/src/db/db/dbPin.cc
@@ -30,13 +30,13 @@ namespace db
 //  Pin class implementation
 
 Pin::Pin ()
-  : m_id (0)
+  : db::NetlistObject (), m_id (0)
 {
   //  .. nothing yet ..
 }
 
 Pin::Pin (const std::string &name)
-  : m_name (name), m_id (0)
+  : db::NetlistObject (), m_name (name), m_id (0)
 {
   //  .. nothing yet ..
 }
diff --git a/src/db/db/dbPin.h b/src/db/db/dbPin.h
index 1c9dd9714..ed77d701f 100644
--- a/src/db/db/dbPin.h
+++ b/src/db/db/dbPin.h
@@ -24,6 +24,7 @@
 #define _HDR_dbPin
 
 #include "dbCommon.h"
+#include "dbNetlistObject.h"
 
 #include <string>
 
@@ -36,6 +37,7 @@ namespace db
  *  A pin is some place other nets can connect to a circuit.
  */
 class DB_PUBLIC Pin
+  : public db::NetlistObject
 {
 public:
   /**
@@ -70,6 +72,15 @@ public:
     return m_id;
   }
 
+  /**
+   *  @brief Sets the name of the pin
+   *  CAUTION: don't use this method on pins stored inside a netlist.
+   */
+  void set_name (const std::string &name)
+  {
+    m_name = name;
+  }
+
 private:
   friend class Circuit;
 
@@ -80,11 +91,6 @@ private:
   {
     m_id = id;
   }
-
-  void set_name (const std::string &name)
-  {
-    m_name = name;
-  }
 };
 
 }
diff --git a/src/db/db/dbSubCircuit.cc b/src/db/db/dbSubCircuit.cc
index 4db7dfa6c..78c123992 100644
--- a/src/db/db/dbSubCircuit.cc
+++ b/src/db/db/dbSubCircuit.cc
@@ -30,7 +30,7 @@ namespace db
 //  SubCircuit class implementation
 
 SubCircuit::SubCircuit ()
-  : m_id (0), mp_circuit (0)
+  : db::NetlistObject (), m_id (0), mp_circuit (0)
 {
   //  .. nothing yet ..
 }
@@ -45,13 +45,13 @@ SubCircuit::~SubCircuit()
 }
 
 SubCircuit::SubCircuit (Circuit *circuit, const std::string &name)
-  : m_circuit_ref (0), m_name (name), m_id (0), mp_circuit (0)
+  : db::NetlistObject (), m_circuit_ref (0), m_name (name), m_id (0), mp_circuit (0)
 {
   set_circuit_ref (circuit);
 }
 
 SubCircuit::SubCircuit (const SubCircuit &other)
-  : tl::Object (other), m_id (0), mp_circuit (0)
+  : db::NetlistObject (other), m_id (0), mp_circuit (0)
 {
   operator= (other);
 }
@@ -59,6 +59,7 @@ SubCircuit::SubCircuit (const SubCircuit &other)
 SubCircuit &SubCircuit::operator= (const SubCircuit &other)
 {
   if (this != &other) {
+    db::NetlistObject::operator= (other);
     m_name = other.m_name;
     m_trans = other.m_trans;
     set_circuit_ref (const_cast<Circuit *> (other.circuit_ref ()));
diff --git a/src/db/db/dbSubCircuit.h b/src/db/db/dbSubCircuit.h
index 6a25001c0..970581fa5 100644
--- a/src/db/db/dbSubCircuit.h
+++ b/src/db/db/dbSubCircuit.h
@@ -43,7 +43,7 @@ class Circuit;
  *  This class essentially is a reference to another circuit
  */
 class DB_PUBLIC SubCircuit
-  : public tl::Object
+  : public db::NetlistObject
 {
 public:
   typedef tl::vector<const Net *> connected_net_list;
diff --git a/src/db/db/gsiDeclDbNetlist.cc b/src/db/db/gsiDeclDbNetlist.cc
index 85f985571..6d2ca28cd 100644
--- a/src/db/db/gsiDeclDbNetlist.cc
+++ b/src/db/db/gsiDeclDbNetlist.cc
@@ -34,7 +34,33 @@
 namespace gsi
 {
 
-Class<db::Pin> decl_dbPin ("db", "Pin",
+static std::vector<tl::Variant> property_keys (const db::NetlistObject *object)
+{
+  std::vector<tl::Variant> v;
+  for (db::NetlistObject::property_iterator p = object->begin_properties (); p != object->end_properties (); ++p) {
+    v.push_back (p->first);
+  }
+  return v;
+}
+
+Class<db::NetlistObject> decl_dbNetlistObject ("db", "NetlistObject",
+  gsi::method ("property", &db::NetlistObject::property, gsi::arg ("key"),
+    "@brief Gets the property value for the given key or nil if there is no value with this key."
+  ) +
+  gsi::method ("set_property", &db::NetlistObject::set_property, gsi::arg ("key"), gsi::arg ("value"),
+    "@brief Sets the property value for the given key.\n"
+    "Use a nil value to erase the property with this key."
+  ) +
+  gsi::method_ext ("property_keys", &property_keys,
+    "@brief Gets the keys for the properties stored in this object."
+  ),
+  "@brief The base class for some netlist objects.\n"
+  "The main purpose of this class is to supply user properties for netlist objects.\n"
+  "\n"
+  "This class has been introduced in version 0.26.2"
+);
+
+Class<db::Pin> decl_dbPin (decl_dbNetlistObject, "db", "Pin",
   gsi::method ("id", &db::Pin::id,
     "@brief Gets the ID of the pin.\n"
   ) +
@@ -225,7 +251,7 @@ static void add_other_abstracts (db::Device *device, const db::DeviceAbstractRef
   device->other_abstracts ().push_back (ref);
 }
 
-Class<db::Device> decl_dbDevice ("db", "Device",
+Class<db::Device> decl_dbDevice (decl_dbNetlistObject, "db", "Device",
   gsi::method ("device_class", &db::Device::device_class,
     "@brief Gets the device class the device belongs to.\n"
   ) +
@@ -397,7 +423,7 @@ static void subcircuit_disconnect_pin1 (db::SubCircuit *subcircuit, const db::Pi
   }
 }
 
-Class<db::SubCircuit> decl_dbSubCircuit ("db", "SubCircuit",
+Class<db::SubCircuit> decl_dbSubCircuit (decl_dbNetlistObject, "db", "SubCircuit",
   gsi::method ("circuit_ref", (const db::Circuit *(db::SubCircuit::*) () const) &db::SubCircuit::circuit_ref,
     "@brief Gets the circuit referenced by the subcircuit.\n"
   ) +
@@ -516,7 +542,7 @@ Class<db::NetSubcircuitPinRef> decl_dbNetSubcircuitPinRef ("db", "NetSubcircuitP
   "This class has been added in version 0.26."
 );
 
-Class<db::Net> decl_dbNet ("db", "Net",
+Class<db::Net> decl_dbNet (decl_dbNetlistObject, "db", "Net",
   gsi::method ("circuit", (db::Circuit *(db::Net::*) ()) &db::Net::circuit,
     "@brief Gets the circuit the net lives in."
   ) +
@@ -1098,8 +1124,8 @@ static void circuit_disconnect_pin1 (db::Circuit *c, const db::Pin *pin)
   }
 }
 
-Class<db::Circuit> decl_dbCircuit ("db", "Circuit",
-  gsi::method ("create_pin", &db::Circuit::add_pin, gsi::arg ("name"),
+Class<db::Circuit> decl_dbCircuit (decl_dbNetlistObject, "db", "Circuit",
+  gsi::method ("create_pin", (const db::Pin &(db::Circuit::*) (const std::string &)) &db::Circuit::add_pin, gsi::arg ("name"),
     "@brief Creates a new \\Pin object inside the circuit\n"
     "This object will describe a pin of the circuit. A circuit connects "
     "to the outside through such a pin. The pin is added after all existing "
@@ -1147,11 +1173,11 @@ Class<db::Circuit> decl_dbCircuit ("db", "Circuit",
     "@brief Gets the net object for a given name.\n"
     "If the ID is not a valid net name, nil is returned."
   ) +
-  gsi::method ("pin_by_id", &db::Circuit::pin_by_id, gsi::arg ("id"),
+  gsi::method ("pin_by_id", (db::Pin *(db::Circuit::*) (size_t)) &db::Circuit::pin_by_id, gsi::arg ("id"),
     "@brief Gets the \\Pin object corresponding to a specific ID\n"
     "If the ID is not a valid pin ID, nil is returned."
   ) +
-  gsi::method ("pin_by_name", &db::Circuit::pin_by_name, gsi::arg ("name"),
+  gsi::method ("pin_by_name", (db::Pin *(db::Circuit::*) (const std::string &)) &db::Circuit::pin_by_name, gsi::arg ("name"),
     "@brief Gets the \\Pin object corresponding to a specific name\n"
     "If the ID is not a valid pin name, nil is returned."
   ) +
diff --git a/src/db/unit_tests/dbLayoutToNetlistReaderTests.cc b/src/db/unit_tests/dbLayoutToNetlistReaderTests.cc
index 5f637911d..cc3c0fb90 100644
--- a/src/db/unit_tests/dbLayoutToNetlistReaderTests.cc
+++ b/src/db/unit_tests/dbLayoutToNetlistReaderTests.cc
@@ -254,7 +254,7 @@ TEST(1b_ReaderBasicShort)
 
   //  verify against the input
 
-  std::string path = tmp_file ("tmp_l2nreader_2.txt");
+  std::string path = tmp_file ("tmp.txt");
   {
     tl::OutputStream stream (path);
     db::LayoutToNetlistStandardWriter writer (stream, true);
@@ -266,6 +266,60 @@ TEST(1b_ReaderBasicShort)
   compare_text_files (path, au_path);
 }
 
+TEST(1c_ReaderBasicShortWithProps)
+{
+  db::LayoutToNetlist l2n;
+
+  std::string in_path = tl::combine_path (tl::combine_path (tl::combine_path (tl::testsrc (), "testdata"), "algo"), "l2n_writer_au_p.txt");
+  tl::InputStream is_in (in_path);
+
+  db::LayoutToNetlistStandardReader reader (is_in);
+  reader.read (&l2n);
+
+  //  verify against the input
+
+  std::string path = tmp_file ("tmp.txt");
+  {
+    tl::OutputStream stream (path);
+    db::LayoutToNetlistStandardWriter writer (stream, true);
+    writer.write (&l2n);
+  }
+
+  std::string au_path = tl::combine_path (tl::combine_path (tl::combine_path (tl::testsrc (), "testdata"), "algo"), "l2n_writer_au_p.txt");
+
+  compare_text_files (path, au_path);
+
+  {
+    db::Layout ly2;
+    ly2.dbu (l2n.internal_layout ()->dbu ());
+    db::Cell &top2 = ly2.cell (ly2.add_cell ("TOP"));
+
+    std::map<unsigned int, const db::Region *> lmap;
+    lmap [ly2.insert_layer (db::LayerProperties (3, 0))] = l2n.layer_by_name ("poly");
+    lmap [ly2.insert_layer (db::LayerProperties (3, 1))] = l2n.layer_by_name ("poly_lbl");
+    lmap [ly2.insert_layer (db::LayerProperties (4, 0))] = l2n.layer_by_name ("diff_cont");
+    lmap [ly2.insert_layer (db::LayerProperties (5, 0))] = l2n.layer_by_name ("poly_cont");
+    lmap [ly2.insert_layer (db::LayerProperties (6, 0))] = l2n.layer_by_name ("metal1");
+    lmap [ly2.insert_layer (db::LayerProperties (6, 1))] = l2n.layer_by_name ("metal1_lbl");
+    lmap [ly2.insert_layer (db::LayerProperties (7, 0))] = l2n.layer_by_name ("via1");
+    lmap [ly2.insert_layer (db::LayerProperties (8, 0))] = l2n.layer_by_name ("metal2");
+    lmap [ly2.insert_layer (db::LayerProperties (8, 1))] = l2n.layer_by_name ("metal2_lbl");
+    lmap [ly2.insert_layer (db::LayerProperties (10, 0))] = l2n.layer_by_name ("psd");
+    lmap [ly2.insert_layer (db::LayerProperties (11, 0))] = l2n.layer_by_name ("nsd");
+
+    db::CellMapping cm = l2n.cell_mapping_into (ly2, top2);
+
+    l2n.build_all_nets (cm, ly2, lmap, "NET_", tl::Variant (), db::LayoutToNetlist::BNH_Disconnected, 0, "DEVICE_");
+
+    std::string au = tl::testsrc ();
+    au = tl::combine_path (au, "testdata");
+    au = tl::combine_path (au, "algo");
+    au = tl::combine_path (au, "l2n_writer_au_p.oas");
+
+    db::compare_layouts (_this, ly2, au, db::WriteOAS);
+  }
+}
+
 TEST(2_ReaderWithGlobalNets)
 {
   db::LayoutToNetlist l2n;
@@ -278,7 +332,7 @@ TEST(2_ReaderWithGlobalNets)
 
   //  verify against the input
 
-  std::string path = tmp_file ("tmp_l2nreader_2.txt");
+  std::string path = tmp_file ("tmp.txt");
   {
     tl::OutputStream stream (path);
     db::LayoutToNetlistStandardWriter writer (stream, false);
@@ -335,7 +389,7 @@ TEST(3_ReaderAbsoluteCoordinates)
 
   //  verify against the input
 
-  std::string path = tmp_file ("tmp_l2nreader_2.txt");
+  std::string path = tmp_file ("tmp.txt");
   {
     tl::OutputStream stream (path);
     db::LayoutToNetlistStandardWriter writer (stream, false);
@@ -394,7 +448,7 @@ TEST(4_ReaderCombinedDevices)
 
   //  verify against the input
 
-  std::string path = tmp_file ("tmp_l2nreader_4.txt");
+  std::string path = tmp_file ("tmp.txt");
   {
     tl::OutputStream stream (path);
     db::LayoutToNetlistStandardWriter writer (stream, false);
diff --git a/src/db/unit_tests/dbLayoutToNetlistWriterTests.cc b/src/db/unit_tests/dbLayoutToNetlistWriterTests.cc
index 2db34248d..9fca0b5fd 100644
--- a/src/db/unit_tests/dbLayoutToNetlistWriterTests.cc
+++ b/src/db/unit_tests/dbLayoutToNetlistWriterTests.cc
@@ -217,6 +217,33 @@ TEST(1_WriterBasic)
 
     db::compare_layouts (_this, ly2, au);
   }
+
+  l2n.netlist ()->begin_circuits ()->set_property (17, 42);
+  l2n.netlist ()->begin_circuits ()->set_property ("a_float", 0.5);
+  l2n.netlist ()->begin_circuits ()->set_property ("a_\"non_quoted\"_string", "s");
+
+  l2n.netlist ()->begin_circuits ()->begin_nets ()->set_property (17, 142);
+  l2n.netlist ()->begin_circuits ()->begin_nets ()->set_property ("a_float", 10.5);
+  l2n.netlist ()->begin_circuits ()->begin_nets ()->set_property ("a_\"non_quoted\"_string", "1s");
+
+  l2n.netlist ()->circuit_by_name ("INV2")->begin_devices ()->set_property (17, 242);
+  l2n.netlist ()->circuit_by_name ("INV2")->begin_devices ()->set_property ("a_float", 20.5);
+  l2n.netlist ()->circuit_by_name ("INV2")->begin_devices ()->set_property ("a_\"non_quoted\"_string", "2s");
+
+  l2n.netlist ()->circuit_by_name ("RINGO")->begin_subcircuits ()->set_property (17, 342);
+  l2n.netlist ()->circuit_by_name ("RINGO")->begin_subcircuits ()->set_property ("a_float", 30.5);
+  l2n.netlist ()->circuit_by_name ("RINGO")->begin_subcircuits ()->set_property ("a_\"non_quoted\"_string", "3s");
+
+  path = tmp_file ("tmp_l2nwriter_1p.txt");
+  {
+    tl::OutputStream stream (path);
+    db::LayoutToNetlistStandardWriter writer (stream, true);
+    writer.write (&l2n);
+  }
+
+  au_path = tl::combine_path (tl::combine_path (tl::combine_path (tl::testsrc (), "testdata"), "algo"), "l2n_writer_au_p.txt");
+
+  compare_text_files (path, au_path);
 }
 
 TEST(2_WriterWithGlobalNets)
diff --git a/src/db/unit_tests/dbNetlistTests.cc b/src/db/unit_tests/dbNetlistTests.cc
index 1dc2f196f..c3056e4aa 100644
--- a/src/db/unit_tests/dbNetlistTests.cc
+++ b/src/db/unit_tests/dbNetlistTests.cc
@@ -344,8 +344,16 @@ TEST(3_CircuitBasic)
   EXPECT_EQ (c.pin_by_name ("p1")->name (), "p1");
   EXPECT_EQ (c.pin_by_name ("doesnt_exist") == 0, true);
   EXPECT_EQ (c.pin_by_name ("p2")->name (), "p2");
+  EXPECT_EQ (c.pin_by_id (0)->begin_properties () == c.pin_by_id (0)->end_properties (), true);
+
+  EXPECT_EQ (c.pin_by_id (0)->property (17).to_string (), "nil");
+  c.pin_by_id (0)->set_property (17, 42);
+  EXPECT_EQ (c.pin_by_id (0)->begin_properties () == c.pin_by_id (0)->end_properties (), false);
+  EXPECT_EQ (c.pin_by_id (0)->begin_properties ()->second.to_string (), "42");
+  EXPECT_EQ (c.pin_by_id (0)->property (17).to_string (), "42");
 
   db::Circuit c2 = c;
+  EXPECT_EQ (c2.pin_by_id (0)->property (17).to_string (), "42");
   EXPECT_EQ (c2.name (), "name");
   EXPECT_EQ (pins2string (c), "p1#0,p2#1");
 
@@ -1419,3 +1427,90 @@ TEST(22_BlankCircuit)
     "end;\n"
   );
 }
+
+TEST(23_NetlistObject)
+{
+  db::NetlistObject nlo;
+  nlo.set_property (1, "hello");
+  EXPECT_EQ (nlo.property ("key").to_string (), "nil");
+  EXPECT_EQ (nlo.property (1).to_string (), "hello");
+  nlo.set_property ("key", 42);
+  EXPECT_EQ (nlo.property ("key").to_string (), "42");
+  nlo.set_property ("key", tl::Variant ());
+  EXPECT_EQ (nlo.property ("key").to_string (), "nil");
+
+  db::Net net ("net_name");
+  net.set_property (1, "hello");
+  EXPECT_EQ (net.property ("key").to_string (), "nil");
+  EXPECT_EQ (net.property (1).to_string (), "hello");
+
+  db::Net net2 (net);
+  EXPECT_EQ (net.property ("key").to_string (), "nil");
+  EXPECT_EQ (net.property (1).to_string (), "hello");
+
+  db::Net net3;
+  EXPECT_EQ (net3.property ("key").to_string (), "nil");
+  EXPECT_EQ (net3.property (1).to_string (), "nil");
+  net3 = net2;
+  EXPECT_EQ (net3.property (1).to_string (), "hello");
+
+  db::SubCircuit sc;
+  sc.set_property (1, "hello");
+  EXPECT_EQ (sc.property ("key").to_string (), "nil");
+  EXPECT_EQ (sc.property (1).to_string (), "hello");
+
+  db::SubCircuit sc2 (sc);
+  EXPECT_EQ (sc.property ("key").to_string (), "nil");
+  EXPECT_EQ (sc.property (1).to_string (), "hello");
+
+  db::SubCircuit sc3;
+  EXPECT_EQ (sc3.property ("key").to_string (), "nil");
+  EXPECT_EQ (sc3.property (1).to_string (), "nil");
+  sc3 = sc2;
+  EXPECT_EQ (sc3.property (1).to_string (), "hello");
+
+  db::Device dev;
+  dev.set_property (1, "hello");
+  EXPECT_EQ (dev.property ("key").to_string (), "nil");
+  EXPECT_EQ (dev.property (1).to_string (), "hello");
+
+  db::Device dev2 (dev);
+  EXPECT_EQ (dev.property ("key").to_string (), "nil");
+  EXPECT_EQ (dev.property (1).to_string (), "hello");
+
+  db::Device dev3;
+  EXPECT_EQ (dev3.property ("key").to_string (), "nil");
+  EXPECT_EQ (dev3.property (1).to_string (), "nil");
+  dev3 = dev2;
+  EXPECT_EQ (dev3.property (1).to_string (), "hello");
+
+  db::Circuit circuit;
+  circuit.set_property (1, "hello");
+  EXPECT_EQ (circuit.property ("key").to_string (), "nil");
+  EXPECT_EQ (circuit.property (1).to_string (), "hello");
+
+  db::Circuit circuit2 (circuit);
+  EXPECT_EQ (circuit.property ("key").to_string (), "nil");
+  EXPECT_EQ (circuit.property (1).to_string (), "hello");
+
+  db::Circuit circuit3;
+  EXPECT_EQ (circuit3.property ("key").to_string (), "nil");
+  EXPECT_EQ (circuit3.property (1).to_string (), "nil");
+  circuit3 = circuit2;
+  EXPECT_EQ (circuit3.property (1).to_string (), "hello");
+
+  db::Pin pin ("pin_name");
+  pin.set_property (1, "hello");
+  EXPECT_EQ (pin.property ("key").to_string (), "nil");
+  EXPECT_EQ (pin.property (1).to_string (), "hello");
+
+  db::Pin pin2 (pin);
+  EXPECT_EQ (pin.property ("key").to_string (), "nil");
+  EXPECT_EQ (pin.property (1).to_string (), "hello");
+
+  db::Pin pin3;
+  EXPECT_EQ (pin3.property ("key").to_string (), "nil");
+  EXPECT_EQ (pin3.property (1).to_string (), "nil");
+  pin3 = pin2;
+  EXPECT_EQ (pin3.property (1).to_string (), "hello");
+}
diff --git a/testdata/algo/l2n_writer_au_p.oas b/testdata/algo/l2n_writer_au_p.oas
new file mode 100644
index 000000000..4db585331
Binary files /dev/null and b/testdata/algo/l2n_writer_au_p.oas differ
diff --git a/testdata/ruby/dbNetlist.rb b/testdata/ruby/dbNetlist.rb
index 1a391a0ba..695eb4e38 100644
--- a/testdata/ruby/dbNetlist.rb
+++ b/testdata/ruby/dbNetlist.rb
@@ -25,6 +25,24 @@ load("test_prologue.rb")
 
 class DBNetlist_TestClass < TestBase
 
+  def test_0_NetlistObject
+
+    nlo = RBA::NetlistObject::new
+    assert_equal(nlo.property(17), nil)
+    assert_equal(nlo.property_keys.inspect, "[]")
+    nlo.set_property(17, 42)
+    assert_equal(nlo.property_keys.inspect, "[17]")
+    assert_equal(nlo.property(17), 42)
+
+    nlo2 = nlo.dup
+    assert_equal(nlo2.property(17), 42)
+    nlo.set_property(17, nil)
+    assert_equal(nlo.property_keys.inspect, "[]")
+    assert_equal(nlo.property(17), nil)
+    assert_equal(nlo2.property(17), 42)
+
+  end
+
   def test_1_NetlistBasicCircuit
 
     nl = RBA::Netlist::new
@@ -141,6 +159,10 @@ class DBNetlist_TestClass < TestBase
     p1 = c.create_pin("A")
     p2 = c.create_pin("B")
 
+    assert_equal(p1.property(17), nil)
+    p1.set_property(17, 42)
+    assert_equal(p1.property(17), 42)
+
     assert_equal(p1.id, 0)
     assert_equal(p2.id, 1)
 
@@ -188,6 +210,10 @@ class DBNetlist_TestClass < TestBase
     assert_equal(c.device_by_id(2).inspect, "nil")
     assert_equal(c.device_by_name("doesnt_exist").inspect, "nil")
 
+    assert_equal(d1.property(17), nil)
+    d1.set_property(17, 42)
+    assert_equal(d1.property(17), 42)
+
     d2 = c.create_device(dc)
     assert_equal(d2.device_class.id, dc.id)
     assert_equal(d2.device_class.object_id, dc.object_id)   # by virtue of Ruby-to-C++ object mapping
@@ -215,6 +241,10 @@ class DBNetlist_TestClass < TestBase
 
     net = c.create_net("NET")
 
+    assert_equal(net.property(17), nil)
+    net.set_property(17, 42)
+    assert_equal(net.property(17), 42)
+
     assert_equal(net.is_floating?, true)
     assert_equal(net.is_internal?, false)
     assert_equal(net.terminal_count, 0)
@@ -370,6 +400,10 @@ class DBNetlist_TestClass < TestBase
     assert_equal(c.subcircuit_by_id(2).inspect, "nil")
     assert_equal(c.subcircuit_by_name("doesnt_exist").inspect, "nil")
 
+    assert_equal(sc1.property(17), nil)
+    sc1.set_property(17, 42)
+    assert_equal(sc1.property(17), 42)
+
     refs = []
     cc.each_ref { |r| refs << r.name }
     assert_equal(refs.join(","), "SC1")
@@ -564,6 +598,10 @@ class DBNetlist_TestClass < TestBase
     c.cell_index = 42
     assert_equal(c.cell_index, 42)
 
+    assert_equal(c.property(17), nil)
+    c.set_property(17, 42)
+    assert_equal(c.property(17), 42)
+
     pina1 = c.create_pin("A1")
     pina2 = c.create_pin("A2")
     pinb1 = c.create_pin("B1")
@@ -581,6 +619,11 @@ class DBNetlist_TestClass < TestBase
     assert_equal(c.pin_by_id(17).inspect, "nil")
     assert_equal(c.pin_by_name("DOESNOTEXIST").inspect, "nil")
 
+    assert_equal(c.pin_by_id(0).property(17), nil)
+    c.pin_by_id(0).set_property(17, 42)
+    assert_equal(c.pin_by_id(0).property(17), 42)
+    assert_equal(c.pin_by_name("A1").property(17), 42)
+
     names = []
     c.each_pin { |p| names << p.name }
     assert_equal(names, [ "A1", "A2", "B1", "B2" ])