diff --git a/doc/OpenSTA.odt b/doc/OpenSTA.odt
index 2953e6b6..5bbf1e11 100644
Binary files a/doc/OpenSTA.odt and b/doc/OpenSTA.odt differ
diff --git a/doc/OpenSTA.pdf b/doc/OpenSTA.pdf
index fd779d57..7d48565e 100644
Binary files a/doc/OpenSTA.pdf and b/doc/OpenSTA.pdf differ
diff --git a/include/sta/Sta.hh b/include/sta/Sta.hh
index 9f3ba651..b8031e05 100644
--- a/include/sta/Sta.hh
+++ b/include/sta/Sta.hh
@@ -753,7 +753,8 @@ public:
 			float slew);
   void writeSdf(const char *filename,
 		Corner *corner,
-		char sdf_divider,
+		char divider,
+                bool include_typ,
 		int digits,
 		bool gzip,
 		bool no_timestamp,
diff --git a/sdf/Sdf.i b/sdf/Sdf.i
index 02782602..57afaa53 100644
--- a/sdf/Sdf.i
+++ b/sdf/Sdf.i
@@ -110,15 +110,16 @@ report_annotated_check_cmd(bool report_setup,
 void
 write_sdf_cmd(char *filename,
 	      Corner *corner,
-	      char sdf_divider,
-	      int digits,
+	      char divider,
+	      bool include_typ,
+              int digits,
 	      bool gzip,
 	      bool no_timestamp,
 	      bool no_version)
 {
   cmdLinkedNetwork();
   Sta *sta = Sta::sta();
-  sta->writeSdf(filename, corner, sdf_divider, digits, gzip,
+  sta->writeSdf(filename, corner, divider, include_typ, digits, gzip,
 		no_timestamp, no_version);
 }
 
diff --git a/sdf/Sdf.tcl b/sdf/Sdf.tcl
index 1cd1c89c..3d3422b4 100644
--- a/sdf/Sdf.tcl
+++ b/sdf/Sdf.tcl
@@ -140,13 +140,13 @@ proc_redirect report_annotated_check {
 }
 
 define_cmd_args "write_sdf" \
-  {[-corner corner_name] [-divider /|.] [-digits digits]\
-     [-gzip] [-no_timestamp] [-no_version] filename}
+  {[-corner corner_name] [-divider /|.] [-include_typ]\
+     [-digits digits] [-gzip] [-no_timestamp] [-no_version] filename}
 
 proc_redirect write_sdf {
   parse_key_args "write_sdf" args \
     keys {-corner -divider -digits -significant_digits} \
-    flags {-gzip -no_timestamp -no_version}
+    flags {-include_typ -gzip -no_timestamp -no_version}
   check_argc_eq1 "write_sdf" $args
   set corner [parse_corner keys]
   set filename [file nativename [lindex $args 0]]
@@ -160,16 +160,14 @@ proc_redirect write_sdf {
   set digits 3
   if [info exists keys(-digits)] {
     set digits $keys(-digits)
+    check_positive_integer "-digits" $digits
   }
-  if [info exists keys(-significant_digits)] {
-    set digits $keys(-significant_digits)
-  }
-  check_positive_integer "-digits" $digits
 
+  set include_typ [info exists flags(-include_typ)]
   set no_timestamp [info exists flags(-no_timestamp)]
   set no_version [info exists flags(-no_version)]
   set gzip [info exists flags(-gzip)]
-  write_sdf_cmd $filename $corner $divider $digits $gzip \
+  write_sdf_cmd $filename $corner $divider $include_typ $digits $gzip \
     $no_timestamp $no_version
 }
 
diff --git a/sdf/SdfWriter.cc b/sdf/SdfWriter.cc
index 98e28cdd..f38aa334 100644
--- a/sdf/SdfWriter.cc
+++ b/sdf/SdfWriter.cc
@@ -47,7 +47,8 @@ public:
   void write(const char *filename,
 	     Corner *corner,
 	     char sdf_divider,
-	     int digits,
+	     bool include_typ,
+             int digits,
 	     bool gzip,
 	     bool no_timestamp,
 	     bool no_version);
@@ -94,10 +95,10 @@ protected:
 			float min_period);
   const char *sdfEdge(const Transition *tr);
   void writeArcDelays(Edge *edge);
-  void writeSdfTuple(RiseFallMinMax &delays,
-		     RiseFall *rf);
-  void writeSdfTuple(float min_delay,
-		     float max_delay);
+  void writeSdfTriple(RiseFallMinMax &delays,
+                      RiseFall *rf);
+  void writeSdfTriple(float min,
+                      float max);
   void writeSdfDelay(double delay);
   char *sdfPortName(const Pin *pin);
   char *sdfPathName(const Pin *pin);
@@ -108,6 +109,7 @@ private:
   DISALLOW_COPY_AND_ASSIGN(SdfWriter);
 
   char sdf_divider_;
+  bool include_typ_;
   float timescale_;
 
   char sdf_escape_;
@@ -124,6 +126,7 @@ void
 writeSdf(const char *filename,
 	 Corner *corner,
 	 char sdf_divider,
+         bool include_typ,
 	 int digits,
 	 bool gzip,
 	 bool no_timestamp,
@@ -131,7 +134,7 @@ writeSdf(const char *filename,
 	 StaState *sta)
 {
   SdfWriter writer(sta);
-  writer.write(filename, corner, sdf_divider, digits, gzip,
+  writer.write(filename, corner, sdf_divider, include_typ, digits, gzip,
 	       no_timestamp, no_version);
 }
 
@@ -152,12 +155,14 @@ void
 SdfWriter::write(const char *filename,
 		 Corner *corner,
 		 char sdf_divider,
+                 bool include_typ,
 		 int digits,
 		 bool gzip,
 		 bool no_timestamp,
 		 bool no_version)
 {
   sdf_divider_ = sdf_divider;
+  include_typ_ = include_typ;
   if (delay_format_ == nullptr)
     delay_format_ = new char[10];
   sprintf(delay_format_, "%%.%df", digits);
@@ -428,45 +433,49 @@ SdfWriter::writeArcDelays(Edge *edge)
   if (delays.hasValue(RiseFall::rise(), MinMax::min())
       && delays.hasValue(RiseFall::fall(), MinMax::min())) {
     // Rise and fall.
-    writeSdfTuple(delays, RiseFall::rise());
+    writeSdfTriple(delays, RiseFall::rise());
     // Merge rise/fall values if they are the same.
     if (!(fuzzyEqual(delays.value(RiseFall::rise(), MinMax::min()),
 		     delays.value(RiseFall::fall(), MinMax::min()))
 	  && fuzzyEqual(delays.value(RiseFall::rise(), MinMax::max()),
 			delays.value(RiseFall::fall(),MinMax::max())))) {
       gzprintf(stream_, " ");
-      writeSdfTuple(delays, RiseFall::fall());
+      writeSdfTriple(delays, RiseFall::fall());
     }
   }
   else if (delays.hasValue(RiseFall::rise(), MinMax::min()))
     // Rise only.
-    writeSdfTuple(delays, RiseFall::rise());
+    writeSdfTriple(delays, RiseFall::rise());
   else if (delays.hasValue(RiseFall::fall(), MinMax::min())) {
     // Fall only.
     gzprintf(stream_, "() ");
-    writeSdfTuple(delays, RiseFall::fall());
+    writeSdfTriple(delays, RiseFall::fall());
   }
 }
 
 void
-SdfWriter::writeSdfTuple(RiseFallMinMax &delays,
-			 RiseFall *rf)
+SdfWriter::writeSdfTriple(RiseFallMinMax &delays,
+                          RiseFall *rf)
 {
-  gzprintf(stream_, "(");
-  writeSdfDelay(delays.value(rf, MinMax::min()));
-  gzprintf(stream_, "::");
-  writeSdfDelay(delays.value(rf, MinMax::max()));
-  gzprintf(stream_, ")");
+  float min = delays.value(rf, MinMax::min());
+  float max = delays.value(rf, MinMax::max());
+  writeSdfTriple(min, max);
 }
 
 void
-SdfWriter::writeSdfTuple(float min_delay,
-			 float max_delay)
+SdfWriter::writeSdfTriple(float min,
+                          float max)
 {
   gzprintf(stream_, "(");
-  writeSdfDelay(min_delay);
-  gzprintf(stream_, "::");
-  writeSdfDelay(max_delay);
+  writeSdfDelay(min);
+  if (include_typ_) {
+    gzprintf(stream_, ":");
+    writeSdfDelay((min + max) / 2.0);
+    gzprintf(stream_, ":");
+  }
+  else
+    gzprintf(stream_, "::");
+  writeSdfDelay(max);
   gzprintf(stream_, ")");
 }
 
@@ -677,7 +686,7 @@ SdfWriter::writeCheck(Edge *edge,
 
   ArcDelay min_delay = graph_->arcDelay(edge, arc, arc_delay_min_index_);
   ArcDelay max_delay = graph_->arcDelay(edge, arc, arc_delay_max_index_);
-  writeSdfTuple(delayAsFloat(min_delay), delayAsFloat(max_delay));
+  writeSdfTriple(delayAsFloat(min_delay), delayAsFloat(max_delay));
 
   gzprintf(stream_, ")\n");
 }
@@ -691,7 +700,7 @@ SdfWriter::writeWidthCheck(const Pin *pin,
   gzprintf(stream_, "    (WIDTH (%s %s) ",
 	   sdfEdge(hi_low->asTransition()),
 	   sdfPortName(pin));
-  writeSdfTuple(min_width, max_width);
+  writeSdfTriple(min_width, max_width);
   gzprintf(stream_, ")\n");
 }
 
@@ -701,7 +710,7 @@ SdfWriter::writePeriodCheck(const Pin *pin,
 {
   gzprintf(stream_, "    (PERIOD %s ",
 	   sdfPortName(pin));
-  writeSdfTuple(min_period, min_period);
+  writeSdfTriple(min_period, min_period);
   gzprintf(stream_, ")\n");
 }
 
diff --git a/sdf/SdfWriter.hh b/sdf/SdfWriter.hh
index 098da8b9..fde76878 100644
--- a/sdf/SdfWriter.hh
+++ b/sdf/SdfWriter.hh
@@ -24,7 +24,8 @@ class Corner;
 void
 writeSdf(const char *filename,
 	 Corner *corner,
-	 char sdf_divider,
+	 char divider,
+         bool include_typ,
 	 int digits,
 	 bool gzip,
 	 bool no_timestamp,
diff --git a/search/Sta.cc b/search/Sta.cc
index 717afd46..61ffb7c4 100644
--- a/search/Sta.cc
+++ b/search/Sta.cc
@@ -3524,15 +3524,16 @@ Sta::setAnnotatedSlew(Vertex *vertex,
 void
 Sta::writeSdf(const char *filename,
 	      Corner *corner,
-	      char sdf_divider,
-	      int digits,
+	      char divider,
+	      bool include_typ,
+              int digits,
 	      bool gzip,
 	      bool no_timestamp,
 	      bool no_version)
 {
   findDelays();
-  sta::writeSdf(filename, corner, sdf_divider, digits, gzip, no_timestamp,
-		no_version, this);
+  sta::writeSdf(filename, corner, divider, include_typ, digits, gzip,
+                no_timestamp, no_version, this);
 }
 
 void