That fact is what causes the disconnect on folks trying to make a rational analysis of the DEM charge that Rove (or anybody else for that matter) could have "outed" Plame in 2002 or 2003.
Does "covert" equal "deep cover?" How deep does the cover have to be before an agent is covert? How covert do they have to be before they have deep cover? Hehehehehe. All that is set out, from a criminal prosecution point, in 50 USC 426.
TITLE 50 : CHAPTER 15 : SUBCHAPTER IV--PROTECTION OF CERTAIN NATIONAL SECURITY INFORMATION 50 USC 421 - Protection of identities of certain United States undercover ...
50 USC 426 - Definitions
Cover overseas has been a real problem. The Foreign Service Nationals can identify most of the American employees who work for the Agency. Being integrated into another USG agency or working for an overseas commerical company help, but there are plenty of telltale signs that foreign intelligence agencies can use to figure out who is who. The Agency is constantly working on ways to improve cover.