The most interesting thing about Bren Derlin is the actor who played him. John Ratzenberger, who is famously known as the know-it-all mailman Cliff Clavin from Cheers, disguised his face (sweet mustache) and voice for this role. It was a little before Cheers, but you would never know it was him.
Bren Derlin was a male Human officer of the Rebel Alliance. Bearing the rank of Major, Derlin served as the operations and security chief at Echo Base, the Alliance headquarters on the planet Hoth, under the command of General Carlist Rieekan. In that post, Derlin had to order the closing of the base door to avoid putting the whole base in risk. By doing so, however, he risked the lives of Luke Skywalker and Han Solo, two valuable Rebels. Soon after that event, Derlin served during the Battle of Hoth. During the Battle of Endor, Derlin served as Unit leader.