diff --git a/gen_etl_graph_highway_name.sh b/gen_etl_graph_highway_name.sh
new file mode 100755
index 00000000..39afd79f
--- /dev/null
+++ b/gen_etl_graph_highway_name.sh
@@ -0,0 +1,19 @@
+
+
+DOT=highway_name.dot
+
+echo "digraph G
+{    
+rankdir=LR;
+" > $DOT
+
+cat ./layers/highway_name/layer.sql          | grep "\-\- etldoc:" |  sed 's/-- etldoc://g' >>$DOT
+cat ./layers/highway_name/merge_highways.sql | grep "\-\- etldoc:" |  sed 's/-- etldoc://g' >>$DOT 
+
+echo "
+}
+" >> $DOT
+
+cat $DOT
+
+dot -Tpng $DOT > layer_highway_names_etl.png
diff --git a/layers/highway_name/layer.sql b/layers/highway_name/layer.sql
index c9c27a86..100b1fc7 100644
--- a/layers/highway_name/layer.sql
+++ b/layers/highway_name/layer.sql
@@ -1,31 +1,49 @@
+
+-- etldoc: layer_highway_name[shape=record fillcolor=lightpink, style="rounded,filled",  
+-- etldoc:     label="layer_highway_name | <z8> z8 |<z9> z9 |<z10> z10 |<z11> z11 |<z12> z12|<z13> z13|<z14_> z14_" ] ;
+
 CREATE OR REPLACE FUNCTION layer_highway_name(bbox geometry, zoom_level integer)
 RETURNS TABLE(osm_id bigint, geometry geometry, name text, ref text, ref_length int, class highway_class, subclass text) AS $$
     SELECT osm_id, geometry, name,
       NULLIF(ref, ''), NULLIF(LENGTH(ref), 0) AS ref_length,
       to_highway_class(highway) AS class, highway AS subclass
     FROM (
+
+        -- etldoc: osm_highway_name_linestring_gen3 ->  layer_highway_name:z8
         SELECT * FROM osm_highway_name_linestring_gen3
         WHERE zoom_level = 8
         UNION ALL
+
+        -- etldoc: osm_highway_name_linestring_gen2 ->  layer_highway_name:z9
         SELECT * FROM osm_highway_name_linestring_gen2
         WHERE zoom_level = 9
         UNION ALL
+
+        -- etldoc: osm_highway_name_linestring_gen1 ->  layer_highway_name:z10 
+        -- etldoc: osm_highway_name_linestring_gen1 ->  layer_highway_name:z11          
         SELECT * FROM osm_highway_name_linestring_gen1
         WHERE zoom_level BETWEEN 10 AND 11
         UNION ALL
+
+        -- etldoc: osm_highway_name_linestring ->  layer_highway_name:z12        
         SELECT * FROM osm_highway_name_linestring
         WHERE zoom_level = 12
             AND LineLabel(zoom_level, COALESCE(NULLIF(name, ''), ref), geometry)
             AND to_highway_class(highway) < 'minor_road'::highway_class
             AND NOT highway_is_link(highway)
         UNION ALL
+
+        -- etldoc: osm_highway_name_linestring ->  layer_highway_name:z13
         SELECT * FROM osm_highway_name_linestring
         WHERE zoom_level = 13
             AND LineLabel(zoom_level, COALESCE(NULLIF(name, ''), ref), geometry)
             AND to_highway_class(highway) < 'path'::highway_class
         UNION ALL
+
+        -- etldoc: osm_highway_name_linestring ->  layer_highway_name:z14_
         SELECT * FROM osm_highway_name_linestring
         WHERE zoom_level >= 14
+
     ) AS zoom_levels
     WHERE geometry && bbox
     ORDER BY z_order ASC;
diff --git a/layers/highway_name/merge_highways.sql b/layers/highway_name/merge_highways.sql
index 0f03c298..a96f6d14 100644
--- a/layers/highway_name/merge_highways.sql
+++ b/layers/highway_name/merge_highways.sql
@@ -2,6 +2,8 @@
 -- stitch together the touching ways with the same name
 -- to allow for nice label rendering
 -- Because this works well for roads that do not have relations as well
+
+-- etldoc: osm_highway_linestring ->  osm_highway_name_linestring
 CREATE TABLE IF NOT EXISTS osm_highway_name_linestring AS (
 	SELECT
 		(ST_Dump(geometry)).geom AS geometry,
@@ -30,6 +32,7 @@ CREATE TABLE IF NOT EXISTS osm_highway_name_linestring AS (
 
 CREATE INDEX IF NOT EXISTS osm_highway_name_linestring_geometry_idx ON osm_highway_name_linestring USING gist(geometry);
 
+-- etldoc: osm_highway_name_linestring -> osm_highway_name_linestring_gen1 
 CREATE TABLE IF NOT EXISTS osm_highway_name_linestring_gen1 AS (
     SELECT ST_Simplify(geometry, 50) AS geometry, osm_id, member_osm_ids, name, ref, highway, z_order
     FROM osm_highway_name_linestring
@@ -37,6 +40,7 @@ CREATE TABLE IF NOT EXISTS osm_highway_name_linestring_gen1 AS (
 );
 CREATE INDEX IF NOT EXISTS osm_highway_name_linestring_gen1_geometry_idx ON osm_highway_name_linestring_gen1 USING gist(geometry);
 
+-- etldoc: osm_highway_name_linestring_gen1 -> osm_highway_name_linestring_gen2
 CREATE TABLE IF NOT EXISTS osm_highway_name_linestring_gen2 AS (
     SELECT ST_Simplify(geometry, 120) AS geometry, osm_id, member_osm_ids, name, ref, highway, z_order
     FROM osm_highway_name_linestring_gen1
@@ -44,6 +48,7 @@ CREATE TABLE IF NOT EXISTS osm_highway_name_linestring_gen2 AS (
 );
 CREATE INDEX IF NOT EXISTS osm_highway_name_linestring_gen2_geometry_idx ON osm_highway_name_linestring_gen2 USING gist(geometry);
 
+-- etldoc: osm_highway_name_linestring_gen2 -> osm_highway_name_linestring_gen3
 CREATE TABLE IF NOT EXISTS osm_highway_name_linestring_gen3 AS (
     SELECT ST_Simplify(geometry, 120) AS geometry, osm_id, member_osm_ids, name, ref, highway, z_order
     FROM osm_highway_name_linestring_gen2