diff --git a/README.md b/README.md
index 9ccc8f2d10ceb7bc52d82526a7c07049f55841ac..9d56d5842a5a448b7d3f4ef88415bc0112fd9df4 100644
--- a/README.md
+++ b/README.md
@@ -11,12 +11,29 @@ Compile
 Install
 -------
 
-* copy jar-file to _/operational_shared/plugins/custom/
+* copy jar-file to _/operational_shared/plugins/custom/_
 
 Configuration
 -------------
 
-* the plugin uses the XML-catalog file specified via plugin settings (if no catalog entry exists an error is reported)
+DTDs
+....
+
+* the plugin uses the XML-catalog file to validate DTD related XML files.
+* the catalog file is specified via plugin settings (if no catalog entry exists an error is reported)
+* the catalog file should be created/modified by `xmlcatalog`.
+* all paths in catalog file should be absolute
+* for tests you could also use env XML_CATALOG_FILES
+* please ensure, your catalog file is correct, you could test it with example ```XML_CATALOG_FILES="$(pwd)/example_catalog/" xmlcatalog example_catalog/catalog "-//NLM//DTD JATS (Z39.96) Journal Publishing DTD v1.1 20151215//EN"```. Replace the last string with the corresponding publicID or systemID.
+
+Schemas
+.......
+
+* the plugin uses local schema files to validate schema/schematron/relaxng related XML files.
+* the schema directory is specified via plugin settings
+
+
+For a (german) introduction how to use it, check https://www.data2type.de/xml-xslt-xslfo/docbook/xml-kataloge 
 
 Copyright hints
 ---------------