Pol SulliVaan was an ambassador of the Givin. When Leia Organa Solo and Luke Skywalker arrived on Yag'Dhul, SulliVaan greeted Leia in a mathematical formula that was different from their standard greeting. Luke Skywalker quickly figured out what the desired result was, and sent a mental image into Leia's mind.
Sources
- The Essential Guide to Alien Species (First mentioned)