(a) Parties to proceedings set forth at § 308.1 of the Uniform Rules and as provided in the Local Rules may obtain discovery only through the production of documents. No other form of discovery shall be allowed.

(b) Any questioning at a deposition of a person producing documents pursuant to a document subpoena shall be strictly limited to the identification of documents produced by that person and a reasonable examination to determine whether the subpoenaed person made an adequate search for, and has produced, all subpoenaed documents.