Due to the potential for unfairness and misunderstanding in making a person who is likely to be indicted testify or produce documents before a grand jury, prosecutors must first attempt to get the target to voluntarily appear. If that doesn’t work, the prosecutor must get the approval of the grand jury and the United States Attorney or the responsible Assistant Attorney General in order to issue a subpoena. (I suspect this is why Rove appeared before the Grand Jury for yet a FIFTH time, if he had not "volunteered", he would have been subpoenaed.
If you’re a “target” (loosely defined as a person against whom the government has evidence of an involvement in a crime for which you may be charged) or a subject of a grand jury investigation, the government may want to question you about your involvement in the crime under investigation. In that case, the United States Attorney’s Manual requires federal prosecutors to advise you in writing of your right to counsel and to use your privilege not to incriminate yourself if you so choose.
If you think you’re the target or subject of a grand jury investigation, you might consider getting a lawyer to open communications with the prosecutor. Sometimes the prosecutor will confirm her intention to indict you, engage in plea negotiations before the indictment, or agree to surrender instead of arrest when the indictment is returned. Other times, the prosecutor will request that the indictment be sealed by the court until your arrest, to reduce the chance you’ll flee to avoid prosecution.
http://www.lawyers.com/lawyers/A~1001633~LDS/FAQ+CRIME+... Edited to add:
9-11.153 Notification of Targets
When a target is not called to testify pursuant to USAM 9-11.150, and does not request to testify on his or her own motion (see USAM 9-11.152), the prosecutor, in appropriate cases, is encouraged to notify such person a reasonable time before seeking an indictment in order to afford him or her an opportunity to testify before the grand jury, subject to the conditions set forth in USAM 9-11.152. Notification would not be appropriate in routine clear cases or when such action might jeopardize the investigation or prosecution because of the likelihood of flight, destruction or fabrication of evidence, endangerment of other witnesses, undue delay or otherwise would be inconsistent with the ends of justice.
http://www.usdoj.gov/usao/eousa/foia_reading_room/usam/... I have little doubt Mr. Rove received such notification from Mr. Fitzgerald regardless of what Mr. Luskin may say.