Special Edition pieces were created to add an extra incentive to buy a boxed set. They were also used to promote the Warhammer and 40k game boxes for Christmas 1999. A series of Army Standard Bearers and other items were then released in the new Army boxes from 2000 until 2007. After that the army / battalion box contents became all plastic models and special editions were discontinued, until the Warhammer 40,000 Dark Vengeance set was released in 2012.
Some of these were also available through the Skulz program.