The invention relates to a novel process for preparing 4,6-dichloro-5-pyrimidine. The updated equalization weights can be obtained using the old equalization weights already computed for initial interference cancellation. In addition, the radical nitriding process causes less plasma damage, in comparison with a conventional simple plasma nitriding process. A frame includes respective openings which receive the pins and a first end of each said sleeves. The apparatus includes first and second parts pivotably mounted to one another, one part including a window through which the item to be displayed may be viewed, one part including a catch element for limiting relative rotation of the two parts, and one part including a hook or screw for mounting the apparatus on a wall.