the scores or notches 31 can be easily removed with a chisel and hammer removal of such a portion will have the effect of advancing abutment portion 17a of inner surface 17 closer to face surface 16 thereby lessening the horizontal offset spacing between blocks 11 in successive courses and consequently the amount of backslope in the wall 10 the amount of backslope may similarly be altered by removing a portion of abutment member 24 abutment member 24 may also have one or more scores or notches 33 running essentially parallel to front surface 26 one or more portions of the abutment member 24 may be easily removed by a chisel and hammer to alter the width of the abutment member 24 it will be evident that changing the width of the abutment member 24 in this fashion will also change the amount of horizontal offset spacing between successive courses and consequently the backslope of the wall 10 a modification of a block 11 for use on tightly curved wall segments is best seen in fig7 in order to accommodate the short radius of curvature a side of the tail portion 14 may be easily removed by placing a chisel on top surface 22 in extension of one side of web portion 15 and striking it with a hammer another modification of a block 11 for use on right angle.