Difference between nodoc and inheritdoc

[rafdulaf]

If I have a subclass that override a method of its parent.
Even with all warnings on (also nodoc), I can put nodoc on the overriden method.

The associated doc is that in my subclass, the method appears to be related to its parent : the override is not displayed.

If I manually add /** @inheritdoc */ everything is fine.

Is this the normal behavior ?
Should'nt we have the same doc with or without /** @inheritdoc */ alone ?
Or could we have a warning when an inherited method has no doc ? (because we currently have an issue with this 468)