What is a key requirement for a claim to avoid a 112 6th paragraph rejection?

A key requirement for a claim to avoid a 112 paragraph 6 rejection is that the claim must clearly define the means for performing the function described within the specification. This provision of the U.S. patent law pertains to functional claims that describe an invention in terms of what it does rather than how it is structured or composed.

When a claim refers to a means for achieving a certain function, the specification must provide enough detail about the corresponding structure or method that performs this function. This avoids ambiguity regarding how the function is achieved and ensures that someone skilled in the art can ascertain the boundaries of the claimed invention. If the claim lacks sufficient structure or detail in its description of the means, it may be interpreted too broadly, leading to a rejection under this provision.

In contrast, while claims must be novel and non-obvious to be patentable (which pertains to C), that requirement does not specifically relate to the structure-function relationship captured by means-plus-function claims. Moreover, requirements relating to existing patents (D) do not pertain to this particular rejection, nor does merely describing a product's structure (A) necessarily address the means-plus-function aspect required to avoid a 112 6 rejection.