diff --git a/README.md b/README.md
index 1570f31..c9ac79d 100644
--- a/README.md
+++ b/README.md
@@ -110,12 +110,13 @@ def fail_write() -> None:
 * Only `uint32`, `int32` (and range of them) can be used as index.
 
 ### Kernel Only class
-* Annotate the class with `@kernel`.
-* Functions are all kernel only, including constructor.
-
-Questions:
-* Should we also do `@portable`?
-* Support inheritance and polymorphism?
+* Annotate the class with `@kernel`/`@portable`.
+* The instance can be created from within kernel functions, or the host if it is
+  portable. It can be passed into kernels.
+* All methods, including the constructor, are treated as kernel/portable
+  functions that would be compiled by the compiler, no RPC function is allowed.
+* If the instance is passed into the kernel, the host is not allowed to access
+  the instance data. Access would raise exception.
 
 ## Generics
 We use [type variable](https://docs.python.org/3/library/typing.html#typing.TypeVar) for denoting generics.