In my last article, I began an almost endless discussion about the claims of a patent application. As a recap, the claims are the real meat of a patent. The examiner will review the claims to determine what about your invention (if anything) is new, and to what scope your invention is patentable. In fact, the vast majority of the prosecution stage of applying for a patent is based around defending the claims against an examiner’s rejections and objections. To clarify, rejections are made over the subject matter of the claims. Conversely, objections are typically made over noncompliance with a required format for the claim.
One of the most well known objections among inventors and patent practitioners involves indefiniteness of a claim, or wherein the claim contains words or phrases whose meaning is unclear. More specifically, a claim may be objected to for lacking antecedent basis. But, what exactly is antecedent basis?
Typically, when drafting claims, an inventor (or the patent attorney representing the inventor) will initially disclose an element of the invention using the article, “a” or “an.” Every subsequent reference to that disclosed element will likely be preceded by “the” or “said.” The Manual of Patent Examining Procedure (MPEP) includes the following on antecedent basis at 2173.05(e):
The lack of clarity could arise where a claim refers to “said lever” or “the lever,” where the claim contains no earlier recitation or limitation of a lever and where it would be unclear as to what element the limitation was making reference. Similarly, if two different levers are recited earlier in the claim, the recitation of “said lever” in the same or subsequent claim would be unclear where it is uncertain which of the two levers was intended. A claim which refers to “said aluminum lever,” but recites only “a lever” earlier in the claim, is indefinite because it is uncertain as to the lever to which reference is made. Obviously, however, the failure to provide explicit antecedent basis for terms does not always render a claim indefinite. If the scope of a claim would be reasonably ascertainable by those skilled in the art, then the claim is not indefinite.
Claims are often very complex, and certainly not easy to read. Plus, with a large number of elements being recited, it is not impossible to mistakenly use refer to “the thing” before first calling it “a thing.” So, what is a person to do if he or she makes an mistake that results in the lack of antecedent basis? The MPEP continues on, stating:
Antecedent problems in the claims are typically drafting oversights that are easily corrected once they are brought to the attention of applicant. The examiner’s task of making sure the claim language complies with the requirements of the statute should be carried out in a positive and constructive way, so that minor problems can be identified and easily corrected, and so that the major effort is expended on more substantive issues. However, even though indefiniteness in claim language is of semantic origin, it is not rendered unobjectionable simply because it could have been corrected.
In practice, patent examiners will often point out issues with antecedent basis to be corrected by the inventor. Besides, the examiner will typically cite and rely on some form of prior art in a rejection as a basis for an invention not being patentable.