diff --git a/stock/src/main/java/de/srsoftware/umbrella/stock/StockModule.java b/stock/src/main/java/de/srsoftware/umbrella/stock/StockModule.java
index 99e13e7..9096f0e 100644
--- a/stock/src/main/java/de/srsoftware/umbrella/stock/StockModule.java
+++ b/stock/src/main/java/de/srsoftware/umbrella/stock/StockModule.java
@@ -1,6 +1,7 @@
 /* © SRSoftware 2025 */
 package de.srsoftware.umbrella.stock;
 
+import static de.srsoftware.tools.Optionals.is0;
 import static de.srsoftware.tools.Optionals.nullIfEmpty;
 import static de.srsoftware.umbrella.core.ConnectionProvider.connect;
 import static de.srsoftware.umbrella.core.Constants.*;
@@ -252,6 +253,11 @@ public class StockModule extends BaseHandler implements StockService {
 			if (parentId.longValue() != 0L) {
 				var target = stockDb.loadLocation(parentId.longValue());
 				if (target.id() == location.id()) throw forbidden("Location must not be it`s own parent!");
+				var current = target;
+				while (current != null){
+					if (current.id() == locationId) throw forbidden("Location cannot be contained in itself!");
+					current = is0(current.parent()) ? null : stockDb.loadLocation(current.parent());
+				}
 				var targetOwner = target.owner().resolve();
 				if (!assigned(targetOwner, user)) throw forbidden("You are not allowed to edit \"{0}\"!", target.name());
 				if (!targetOwner.equals(owner))   throw unprocessable("You may not move locations from one owner ({0}) to another ({1})", owner, targetOwner);
diff --git a/translations/src/main/resources/de.json b/translations/src/main/resources/de.json
index 89aa252..f36deba 100644
--- a/translations/src/main/resources/de.json
+++ b/translations/src/main/resources/de.json
@@ -141,7 +141,7 @@
   "logout_user": "{user} abmelden",
 
   "markdown_code": "Markdown-Code",
-  "markdown_supported": "Markdown & <a href=\"https://plantuml.com\">Plantuml</a> nutzbar!",
+  "markdown_supported": "Markdown & <a target=\"_blank\" href=\"https://plantuml.com\">Plantuml</a> nutzbar!",
   "MANAGE_LOGIN_SERVICES": "Login-Services verwalten",
   "member": "Mitarbeiter",
   "members": "Mitarbeiter",
diff --git a/translations/src/main/resources/en.json b/translations/src/main/resources/en.json
index 3d8613d..34a8f4f 100644
--- a/translations/src/main/resources/en.json
+++ b/translations/src/main/resources/en.json
@@ -140,7 +140,7 @@
   "logout_user": "logout {user}",
 
   "markdown_code": "Markdown-Code",
-  "markdown_supported": "Markdown & <a href=\"https://plantuml.com\">Plantuml</a> supported!",
+  "markdown_supported": "Markdown & <a target=\"_blank\" href=\"https://plantuml.com\">Plantuml</a> supported!",
   "MANAGE_LOGIN_SERVICES": "manage login services",
   "member": "member",
   "members": "members",