What does it mean if a claim is "impervious" to a double-patenting rejection?

When a claim is described as "impervious" to a double-patenting rejection, it indicates that the claim can only be pursued in a divisional application. This terminology often refers to situations where the claims are so distinctly separate from those in the original application that they do not share the same inventive concept or subject matter, thereby allowing for the pursuit of a divisional application to avoid issues of double patenting that would arise if the claims were to be presented in a continuation application.

Double patenting typically occurs when two patents cover the same invention or obvious variations of it. However, if a claim is impervious to such rejections, it suggests that the claim is not only unique but also protects distinct subject matter that justifies its filing as a divisional application, separate from the parent application. This separation allows for the development and protection of new ideas that are not merely variations of what has already been claimed.

In the context of the other potential choices:

• A claim that is immune to additional review doesn’t accurately characterize the legal nuances of patent claims and rejections. All claims are subject to review, even if they are distinct.

• A claim that cannot stand on its own implies a lack of independence in the claim, which contradict