Coordinate filters are useful for creating a new coordinate location using the X value from one location, the Y value of a second location, and the Z value of a third location (or some combination of the three). In 2D, point filters are helpful for identifying centers of rectangles or aligning things at the same X or Y coordinate. To specify a filter on the command line, enter a period and one or more of the letters X, Y, and Z. AutoCAD accepts the following filter selections:
After you specify the initial coordinate value, AutoCAD prompts you for the remaining values. If you enter .x at a prompt to enter a point, you are prompted for the Y and Z values; if you enter .xz, you are prompted for the Y value. The Z value (which for us should always be 0) is carried over from the last point you drew, so if you are prompted for a Z value you can simply select the point with the mouse.