S-4QD was a protocol droid that had been sent to Tilnes as a representative for the droids of Uffel. They quickly realized that Tilnes had no future for droids, but left 4QD there in an advisory capacity. He ended up giving out pieces of esoteric information in conversations which served no purpose in moving that conversation along. He was a grumpy droid who always predicted that the next electromagnetic pulse would finish him off.