Rainbow Six: Rogue Spear Urban Operations

From Rainbow Six Wiki

Rogue Spear: Urban Operations, released on April 4, 2000, was the first expansion for Rogue Spear. It was developed and published by Red Storm Entertainment. It added 8 new maps and 5 classic Rainbow Six maps from the original Rainbow Six game, as well as 3 new weapons

Also, Urban Operations has been re-released by KAMA Digital Entertainment in South Korea - this new edition included two exclusive missions and two new weapons. It was sort of a prequel to Take Down.