Validation removed from METADATA so that it is more generic - it's up to each application to decide how to structure its contents. Existing strict validation applied to a duplicate called QORTAL_METADATA. This will be the one used for website/app listings in the Qortal UI.

src/main/java/org/qortal/arbitrary/misc/Service.java

@@ -27,7 +27,8 @@ public enum Service {
     DOCUMENT(800, false, null, null),
     PLAYLIST(900, true, null, null),
     APP(1000, false, null, null),
-    METADATA(1100, true, 10*1024L, Arrays.asList("title", "description", "tags"));
+    METADATA(1100, false, null, null),
+    QORTAL_METADATA(1111, true, 10*1024L, Arrays.asList("title", "description", "tags"));
 
     public final int value;
     private final boolean requiresValidation;