diff --git a/src/zinc/hal/systick.rs b/src/zinc/hal/systick.rs
index a8c17f8e..035cc7bc 100644
--- a/src/zinc/hal/systick.rs
+++ b/src/zinc/hal/systick.rs
@@ -20,6 +20,8 @@ This might be merged into generic timer interface. Systick is a bit specific in
 terms of interrupts, but PT should make the difference negligible.
 */
 
+/// A simple systick interface.
+#[experimental]
 pub trait Systick {
   /// Starts the systick timer.
   fn start(&self);
diff --git a/src/zinc/os/mod.rs b/src/zinc/os/mod.rs
index b82d2d7e..5f3614e7 100644
--- a/src/zinc/os/mod.rs
+++ b/src/zinc/os/mod.rs
@@ -20,4 +20,5 @@ This module is a higher level abstraction over hardware than hal. It might be
 incompatible direct hal usage in some cases.
 */
 
+#[experimental]
 pub mod sched;
diff --git a/src/zinc/os/sched/mod.rs b/src/zinc/os/sched/mod.rs
index 365bad08..d3e39a0b 100644
--- a/src/zinc/os/sched/mod.rs
+++ b/src/zinc/os/sched/mod.rs
@@ -13,7 +13,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-/// Tasks scheduling and management.
+//! Tasks scheduling and management.
 
 pub mod scheduler;
 pub mod stack;
diff --git a/src/zinc/os/sched/stack.rs b/src/zinc/os/sched/stack.rs
index 2d2f1047..327f71ab 100644
--- a/src/zinc/os/sched/stack.rs
+++ b/src/zinc/os/sched/stack.rs
@@ -13,7 +13,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-/// Tasks stack management.
+//! Tasks stack management.
 
 /// StackManager provides scheduler with interface to manage task-specific stack
 /// pointer.
diff --git a/src/zinc/os/sched/task.rs b/src/zinc/os/sched/task.rs
index 7b896200..ce91a63b 100644
--- a/src/zinc/os/sched/task.rs
+++ b/src/zinc/os/sched/task.rs
@@ -13,7 +13,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-/// Task structures.
+//! Task structures.
 
 use core::kinds::marker;
 
@@ -45,5 +45,6 @@ pub struct TasksIndex<'a> {
   /// Current running task index.
   pub current_task_index: u8,
 
+  /// Tasks are not copyable.
   pub no_copy: marker::NoCopy,
 }