Section 112(a) of Title 35 requires that a patent include a specification containing "a written description of the invention ... in such full, clear, concise, and exact terms as to enable any person skilled in the art... to make and use the same. "

The Federal Circuit held that a patent need not expressly state the absence of a feature in order to support a negative limitation in the specification, and did not identify what, if anything, must be present in the written description to support such a limitation.

The question presented is:

Whether, under 35 U.S.C. § 112(a), a patent specification must include a written description supporting a claimed negative limitation.

Whether, under 35 U.S.C. § 112(a), a patent specification must include a written description supporting a claimed negative limitation