Note that of the aforementioned forms of return yards, kick return yards and punt return yards result from voluntary change in possession and most of the others result from involuntary forms of change in possession known as turnovers. Often kick return and punt return statistics are aggregated. and sometimes they are added to yards from scrimmage to yield all-purpose yards. When kick return yards and punt return yards are aggregated they are known as combined return yards or more formally, combined kick return yards.