No, a pro se litigant--someone representing him- or herself--may send 3rd-party discovery requests (e.g. subpoenas) to persons or business which may have information relevant to the litigation (e.g. a divorce case). The pro se litigant does have to comply with all the same rules and procedures as an attorney would, however; there is no simplied set of rules for pro se litigants. You should be able to download a copy of your state's Rules of Court and sample subpoena or other disovery forms. You'll also have to have the discovery served properly on the 3rd parties, which likely means hiring a process server.