Serusan (or Serosian common) was a shorthand language used as a common trade language by shallow-water races. It was a distinctly an undersea tongue, and contained dolphins' clicks and whistles, words from the sahuagin language language, the aquatic elvish tongue, and the kuo-toan language, it also included some parts from the aquan language, which was used by locathah, merfolk, and shalarin. All these races could speak and understand Serusan, but unless fluent in it as a separate language, they could only grasp the most basic meanings.