The dictionary meaning of nonce word is "a word coined for one single occasion only." From Williamson v. Citrix Online, LLC (Fed. Cir. 2015), use of nonce words that do not connote sufficiently definite structure in claim limitations may invoke 35 USC 112(f) (or pre-AIA 35 USC 112, sixth paragraph). Examples of nonce words that can operate as substitute for means are module, mechanism, element, and device.
35 USC 112(f) (or pre-AIA 35 USC 112, sixth paragraph) states that "[a]n element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof."
The patent in suit in Williamson v. Citrix Online, LLC used the nonce word module in a claim limitation. This limitation reads as follows:
a distributed learning control module for receiving communications transmitted between the presenter and the audience member computer systems and for relaying the communications to an intended receiving computer system and for coordinating the operation of the streaming data module.
The court observed that if the word module is replaced with means, the entire limitation will be consistent with the traditional means-plus-function limitation. The court found that the term "distributed learning control module" falls under pre-AIA 35 USC 112, sixth paragraph because (i) module is a nonce word that can be used as a substitute for means, (ii) modifying module with "distributed learning control" does not impart any structural significance to the meaning of module, and (iii) the claim did not describe how the distributed learning control module interacted with other components in the distributed learning control server so that one may infer the structural character of the limitation.
Having invoked pre-AIA 35 USC 112, sixth paragraph, the specification would need to recite structure corresponding to the term “distributed learning control module” for the claim to be valid. The court found that there was no corresponding supporting structure for the term “distributed learning control module,” rendering the term indefinite and the claim invalid.
The court provided some guidance on what would have been corresponding supporting structure. Specifically, the court noted that it is clear from the specification of the patent that the distributed learning control module must be implemented in a special purpose computer that is programmed to perform particular functions. The opinion of the court makes it clear that the specification should have disclosed an algorithm for performing the claimed function, expressed as a mathematical formula, in prose, as a flow chart, or in any other manner that provides sufficient structure.