; and (ii) the prosecution history pertaining to the patent; and (B) if a court has previously construed a challenged claim of a patent or a challenged claim term in a civil action to which the patent owner was a party, the Office shall consider that claim construction. . (b) Burden of proof Section 326(e) of title 35, United States Code, is amended to read as follows: (e) Evidentiary standards (1) Presumption of validity The presumption of validity under section 282(a) shall apply to a previously issued claim that is challenged during a proceeding under this chapter. (2) Burden of proof In a post-grant review instituted under this chapter, the petitioner shall have the burden of proving a proposition of unpatentability of a previously issued claim by clear and convincing evidence. . (c) Standing Section 321 of title 35, United States Code, is amended by adding at the end the following new subsection: (d) Persons that may petition (1) Definition In this subsection, the term charged with infringement means a real and substantial controversy regarding infringement of a patent exists such that the petitioner would have standing to bring a declaratory judgment action in Federal court. (2) Necessary conditions A person may not file with the Office a petition to institute a post-grant review of the patent unless the person, or a real party in interest or privy of the person, demonstrates— (A) a reasonable possibility of being— (i) sued for infringement of the patent; or (ii) charged with infringement under the patent