The Special Edition Boba Fett costume is often referred to as the RotJ SE costume or simply the SE costume.
For the 20th Anniversary of Star Wars: A New Hope, George Lucas digitally remastered the image and sound of A New Hope, The Empire Strikes Back and Return of the Jedi. He also made a number of controversial changes and additions to the films in order to "finish the film the way it was meant to be." These changes included addition Boba Fett footage in both A New Hope and Return of the Jedi.
The costume used for the additional A New Hope footage is complete the Return of the Jedi Boba Fett Costume. The costume was worn by creature animator, Mark Austin
The costume used for the additional Return of the Jedi footage is complete the Return of the Jedi Boba Fett Costume with the Empire Strikes Back Boba Fett Helmet. The costume was worn by ILM modelmaker, Don Bies
Some touchup was given to both the costume and the helmet for these additional scenes.