diff --git a/docs/assets/images/img-resources-example.png b/docs/assets/images/img-resources-example-1.png
similarity index 100%
rename from docs/assets/images/img-resources-example.png
rename to docs/assets/images/img-resources-example-1.png
diff --git a/docs/assets/images/img-resources-example-2.png b/docs/assets/images/img-resources-example-2.png
new file mode 100644
index 000000000..5973c7fd7
Binary files /dev/null and b/docs/assets/images/img-resources-example-2.png differ
diff --git a/docs/dsp-tools-excel.md b/docs/dsp-tools-excel.md
index 134e21624..3d0efbf57 100644
--- a/docs/dsp-tools-excel.md
+++ b/docs/dsp-tools-excel.md
@@ -8,12 +8,18 @@ list from an Excel file.
 
 ## Create the resources for a data model from an Excel file
 
-With dsp-tools the `resources` section used in a data model (JSON) can be created from an Excel file. Only the first
-worksheet of the Excel file is considered and only `XLSX` files are allowed. The `resources` section can be inserted
-into the ontology file and then be uploaded onto a DSP server.
+With dsp-tools the `resources` section used in a data model (JSON) can be created from an Excel file. Only `XLSX` files
+are allowed. The `resources` section can be inserted into the ontology file and then be uploaded onto a DSP server.
 
-The Excel sheet must have the following format:
-![img-resources-example.png](assets/images/img-resources-example.png)
+The expected worksheets of the Excel file are:
+
+- `classes`: a table with all resource classes intended to be used in the resulting JSON
+- `class1`, `class2`,...: a table for each resource class named after its name
+
+The Excel sheet must have the following format.
+
+The worksheet called `classes` has the following form: 
+![img-resources-example-1.png](assets/images/img-resources-example-1.png)
 
 The expected columns are:
 
@@ -21,6 +27,14 @@ The expected columns are:
 - `super` : The base resource of the resource
 - `en`, `de`, `fr`, `it` : The labels of the resource in different languages, at least one language has to be provided
 
+All other worksheets, one for each resource class, have the following form:
+![img-resources-example-2.png](assets/images/img-resources-example-2.png){ width=50% }
+
+The expected columns are:
+
+- `Property` : The name of the property
+- `Cardinality` : The cardinality, one of: `1`, `0-1`, `1-n`, `0-n`
+
 For further information about resources, see [here](./dsp-tools-create.md#resources).
 
 ## Create the properties for a data model from an Excel file
diff --git a/mkdocs.yml b/mkdocs.yml
index 7b2a142cf..ac03ffbfb 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -24,9 +24,13 @@ theme:
     accent: 'deep blue'
   feature:
     tabs: false
+
 extra_css:
   - 'assets/style/theme.css'
 
+markdown_extensions:
+    - attr_list
+
 plugins:
   - search
   - include-markdown