Yes we skip grades, most common is white (9th kyu) to orange (7th kyu). Dont get it as often as you move higher up the grades, although at the last grading we had a purple belt (4th kyu) double grade to 2nd tab brown (2nd kyu). Was vvvvv unusual but he had double graded all the way through with well over the average marks. Was a black belt in shotokan and rather good i have to say. It also worked out well for me, as he double graded I got the award for highest marks in the overall grading RESULT!!!