Sets an extra avoid area around specified sides of a selected frame for which tfavoid has been enabled. tfgap extends the avoid area of such frames without the need to draw another frame but has no effect on frames which do not have avoid turned on. This can be particularly useful if you have a frame at the top of a column, and want the next column to start level with its bottom edge: if you give the frame a large left gap or right gap, text will not be shown next to the frame.