diff --git a/bookshop/srv/access-control.cds b/bookshop/srv/access-control.cds
index 1cd1ac3c..80384f6e 100644
--- a/bookshop/srv/access-control.cds
+++ b/bookshop/srv/access-control.cds
@@ -1,2 +1,2 @@
 using { AdminService } from './admin-service';
-annotate AdminService with @requires: false; //'admin';
+annotate AdminService with @requires:'admin';
diff --git a/bookshop/srv/admin-service.cds b/bookshop/srv/admin-service.cds
index 855e73d2..37b02eb7 100644
--- a/bookshop/srv/admin-service.cds
+++ b/bookshop/srv/admin-service.cds
@@ -1,6 +1,6 @@
 using { sap.capire.bookshop as my } from '../db/schema';
 service AdminService @(path:'/admin') {
-  entity Authors as projection on my.Authors excluding { books};
+  entity Authors as projection on my.Authors;
   entity Books as projection on my.Books;
   entity Genres as projection on my.Genres;
 }
diff --git a/bookshop/test/dynamic-constraints/readme.md b/bookshop/test/dynamic-constraints/readme.md
new file mode 100644
index 00000000..0ffb974d
--- /dev/null
+++ b/bookshop/test/dynamic-constraints/readme.md
@@ -0,0 +1,26 @@
+## Experimental Dynamic Constraints
+
+This example demonstrates how to use dynamic constraints in a CAP application. It includes a service definition and a test setup to validate the constraints.
+
+
+### Prerequisites
+
+You've setup the [_cap/samples_](https://github.com/sap-samples/cloud-cap-samples) like so:
+
+```sh
+git clone -q https://github.com/sap-samples/cloud-cap-samples cap/samples
+cd cap/samples
+npm install
+```
+
+### Testing
+
+Test like that in `cds.repl` from _cap/samples_ root:
+
+```sh
+cds repl --run bookshop/test/dynamic-constraints
+````
+
+```javascript
+await AdminService.create ('Books', { title:'   ', author_ID:150 })
+```
diff --git a/bookshop/server.js b/bookshop/test/dynamic-constraints/server.js
similarity index 82%
rename from bookshop/server.js
rename to bookshop/test/dynamic-constraints/server.js
index 819c55b7..d7d62fbb 100644
--- a/bookshop/server.js
+++ b/bookshop/test/dynamic-constraints/server.js
@@ -1,9 +1,6 @@
 //
-//  Quick and dirty implementation for cds.validate() using db-level constraints
-//  Test in cds.repl like that:
-//  {Books} = AdminService.entities
-//  await cds.run (()=> INSERT.into (Books, { title:'   ', author_ID:150 }) .then (cds.validate(Books)))
-//  await AdminService.create ('Books', { title:'   ', author_ID:150 })
+// Quick and dirty implementation for cds.validate()
+// using db-level constraints.
 //
 
 const cds = require('@sap/cds')
diff --git a/bookshop/test/dynamic-constraints/srv/admin-service.cds b/bookshop/test/dynamic-constraints/srv/admin-service.cds
new file mode 100644
index 00000000..373501e5
--- /dev/null
+++ b/bookshop/test/dynamic-constraints/srv/admin-service.cds
@@ -0,0 +1,5 @@
+using { AdminService } from '../../../srv/admin-service';
+annotate AdminService with @requires: false;
+extend AdminService.Authors with columns {
+  null as books // to simulate the exclusion of books
+}
diff --git a/bookshop/srv/x-field-control.cds b/bookshop/test/dynamic-constraints/srv/field-control.cds
similarity index 88%
rename from bookshop/srv/x-field-control.cds
rename to bookshop/test/dynamic-constraints/srv/field-control.cds
index 9f96d3ad..3b48b7a3 100644
--- a/bookshop/srv/x-field-control.cds
+++ b/bookshop/test/dynamic-constraints/srv/field-control.cds
@@ -1,5 +1,5 @@
 namespace sap.capire.bookshop;
-using from '../db/schema';
+using from './admin-service';
 
 view Books.field.control as select from Books { ID,
   genre.name == 'Drama' ? 'readonly' :
diff --git a/bookshop/srv/x-validation.cds b/bookshop/test/dynamic-constraints/srv/validation.cds
similarity index 100%
rename from bookshop/srv/x-validation.cds
rename to bookshop/test/dynamic-constraints/srv/validation.cds