The PBAI, in rejecting claim 24:

The statutory categories under 35 U.S.C. § 101 are expressed in the alternative, i.e., process, machine, manufacture or composition of matter. Thus, the appellants' claim 24, which encompasses two statutory categories, i.e., apparatus and method, violates 35 U.S.C. § 101. See Ex parte Lyell, 17 USPQ2d 1548, 1551 (Bd. Pat. App. & Int. 1990).

Moreover, it is unclear whether claim 24 claims an apparatus or a method. Claim 24, therefore, is indefinite in violation of 35 U.S.C. § 112, second paragraph. See Lyell, 17 USPQ2d at 1552.

The Patent Appeals Board itself created the new ground for rejection; the Examiner had flubbed his prior art rejection, the Board ruled.

While there is a clear message that mixing claim types is now a de rigueur no-no, it remains to be seen how common the practice has been to date. Software in particular seems a fertile ground for such mixed-type claims, partly because method claims are natural for that technology type, and corresponding system claims are often a recast of method claims (at least for this prosecutor). There is no evidence, however, that this practice has been widespread; mixed-type claims may be nothing more than an occasional anomaly by overly creative prosecutors and less-persnickety examiners.