diff --git a/pgsql/z-graph/README.md b/pgsql/z-graph/README.md
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+---
+title: "storage-common/pgsql/z-graph"
+date:   2021-02-15
+author:  helmutm
+---
+
+The directory `z-graph` (previously known as `cybergraph`) contains code 
+that is not used any longer but may be of interest for other development, 
+e.g. for the `graph` storage. It has been renamed for 
+
+See especially:
+  - `fload.sql`: functions for loading the semantic database
+  - `fshow.sql`: functions for displaying of information from the semantic database
diff --git a/pgsql/cybergraph/drop.sql b/pgsql/z-graph/drop.sql
similarity index 100%
rename from pgsql/cybergraph/drop.sql
rename to pgsql/z-graph/drop.sql
diff --git a/pgsql/cybergraph/fload.sql b/pgsql/z-graph/fload.sql
similarity index 100%
rename from pgsql/cybergraph/fload.sql
rename to pgsql/z-graph/fload.sql
diff --git a/pgsql/cybergraph/fshow.sql b/pgsql/z-graph/fshow.sql
similarity index 100%
rename from pgsql/cybergraph/fshow.sql
rename to pgsql/z-graph/fshow.sql
diff --git a/pgsql/cybergraph/init.sql b/pgsql/z-graph/init.sql
similarity index 100%
rename from pgsql/cybergraph/init.sql
rename to pgsql/z-graph/init.sql
diff --git a/pgsql/cybergraph/lbase.sql b/pgsql/z-graph/lbase.sql
similarity index 100%
rename from pgsql/cybergraph/lbase.sql
rename to pgsql/z-graph/lbase.sql
diff --git a/pgsql/cybergraph/qtriples.sql b/pgsql/z-graph/qtriples.sql
similarity index 100%
rename from pgsql/cybergraph/qtriples.sql
rename to pgsql/z-graph/qtriples.sql
diff --git a/pgsql/cybergraph/tcreate.sql b/pgsql/z-graph/tcreate.sql
similarity index 100%
rename from pgsql/cybergraph/tcreate.sql
rename to pgsql/z-graph/tcreate.sql
diff --git a/pgsql/cybergraph/tgtriples.sql b/pgsql/z-graph/tgtriples.sql
similarity index 100%
rename from pgsql/cybergraph/tgtriples.sql
rename to pgsql/z-graph/tgtriples.sql
diff --git a/pgsql/cybergraph/vtriples.sql b/pgsql/z-graph/vtriples.sql
similarity index 100%
rename from pgsql/cybergraph/vtriples.sql
rename to pgsql/z-graph/vtriples.sql