Who is Mr. Sipperley from Life with Jeeves and what is their importance?

Mr. Sipperley, better known as Old Sippy, is one of Bertie's old friends. Sippy was once well known for serving thirty days after punching a policeman in the stomach on Boat-Race night. He is currently employed as the editor of the Mayfair Gazette. Sipperley is in love with Gwendolen Moon.