Scala written annotations that subclass `ClassfileAnnotation` are not stored actually as Java annotations as specified, the implementation warns you that: 

```scala
annot-nonconst.scala:2: warning: Implementation restriction: subclassing Classfile does not
make your annotation visible at runtime.  If that is what
you want, you must write the annotation class in Java.
class Ann2(value: String) extends annotation.ClassfileAnnotation
      ^
```