In the first four blanks of the narrative portion of subpoena Form I-138 shall be inserted, respectively, the title of the Service officer before whom the appearance will be made, and the pace, date, and time of appearances. Following the word "with" on the third line, insert the following words, as applicable; (an)(a) exclusion, deportation, status, naturalization, or denaturalization. The name of the subject of the proceedings shall inserted on line five. Following the word "concerning" shall be insert ed, whichever is appropriate, the language: (his)(her) privilege of entering, reentering, residing in, or passing through the United States; or (his)(her) application for the benefits under the said Act; or, (his)(her) eligibility for naturalization; or whether (his)(her) naturalization is subject to revocation.

In interrogating the subpoenaed person, every precaution shall be exercised to confine interrogations clearly within the scope of the nd pertinent to the nature and purpose of the proceeding involved. Documents directed to be produced must be described with sufficient definiteness to enable unmistakable identification and a reasonable period shall be allowed for assembling and production.