Another special form of a claim is a Jepson claim. Jepson claims recite all or some of the elements of a known article, process, composition or combination in the preamble to the claim.

Jepson claims include a transition that states “wherein the improvement comprises” or “the combination with the old article, etc., of.” Jepson claims also recite in the body of the claim the new or modified elements. Alternatively, the body of the Jepson claim identifies new forms of connection or cooperation between old elements.

Jepson claims are generally undesirable claim forms because they are very narrow in scope. Also, Jepson claims are common in some foreign countries and often appear in the American version of the applications.

Here is an example of a Jepson claim

An improved zinc-electroplating solution of the type containing an aqueous solution of zinc acetate, from 30 to 90 grams per liter; citric acid, from 1.5 to 3 times the zinc acetate concentration; and an alkaline pH modifying substance in an amount sufficient to adjust the pH to a value of from 4 to 5.5, wherein the improvement comprises: 0.5 to 1 gram per liter of boric acid.