Snipe in planing refers to a common issue where the planer blade cuts deeper at the beginning or end of a board, leaving a noticeable groove. It happens when the wood is not supported correctly. To avoid snipe, ensure the board is evenly supported throughout its entire length as it enters and exits the planer. You can do this by using support tables or additional rollers at the infeed and outfeed sides of the planer. Properly adjusting the height of the planer blades and reducing the depth of cut can also alleviate snipe. It's important to note that snipe is a common problem that can affect the quality of your woodworking projects, but with proper techniques and adjustments, it can be minimized or eliminated.