Dear Staff and other members, how do I properly add this credit?

Hi IMDb Staff. I worked on the movie "Quasi." I played two different characters. I was a King's Guard, who had dialogue. I was also a different King's Guard, who was an integral part of a scene where I laughed, then did a stunt. Both would be considered main cast. Listed on the call sheet and contract as King's Guard #2. I was credited on screen. In the scene were I have dialogue, I was not named. In the scene were I laugh, I was given a name (Arnaud) by another character in the scene and referred to by that name. How should I credit it?  Should I credit as this ....? Cast: Arnaud / King's Guard #2 or simply King's Guard #2 or neither? And with attributes or without? PS, many cast members played multiple roles on this movie. Thanks for all help and advice. Below are screen shots. PPS, as Arnaud, I had a mustache. As the other Guard, I did not have a mustache.