See Federal Rules of Criminal Procedure
Form, contents and issuance of subpoena, Rule 17(a).
Service in United States, Rule 17(d), (e,1).
Service in foreign country, Rule 17(d), (e,2).
Indigent defendants, Rule 17(b).
On taking depositions, Rule 17(f).
Papers and documents, Rule 17(c).
Disobedience of subpoena as contempt of court, Rule 17(g).