diff --git a/src/ifcopenshell-python/ifcopenshell/express/README.md b/src/ifcopenshell-python/ifcopenshell/express/README.md
index 6def60b872..3c57d4cab5 100644
--- a/src/ifcopenshell-python/ifcopenshell/express/README.md
+++ b/src/ifcopenshell-python/ifcopenshell/express/README.md
@@ -8,11 +8,24 @@ The code can be invoked in the following way and results in several code outputs
 named according to the schema name in the Express file. A python 3 interpreter
 with the `pyparsing` (`pip install pyparsing`) library is required.
 
+note: 
+**Keep in mind that Express is not very suitable for this kind of usage. In the end, (as far as I can tell) no tool is able to read your model, because it doesn't understand the schema as it has no notion of the core part vs the addition.**
+
 ## Command line usage for code generation
 
+The usage for C++ project.
 ~~~
-# python3 bootstrap.py express.bnf > express_parser.py
-python3 express_parser.py IFC2X3_TC1.exp header implementation schema_class definitions
+# bootstrap.py express.bnf in ifcopenshell-python.ifcopenshell.express.
+>>> python3 bootstrap.py express.bnf > express_parser.py
+>>> python3 express_parser.py IFC2X3_TC1.exp header implementation schema_class definitions
+~~~
+
+The usage for python project.
+~~~
+# code rule generation
+# generating 'ifcopenshell.express.rules.IFC2X3_TC1' in ifcopenshell-python.ifcopenshell.express.rules.
+# rule_compiler in ifcopenshell-python.ifcopenshell.express.
+>>> python -m rule_compiler IFC2X3_TC1.exp
 ~~~
 
 ## Programmatic usage