of rotation index markings 35 the diameter of the cover member 30 is greater than the diameter of the modified disc medium 20 such that the cover member may be placed over a stack 21 of modified disc media 20 yet less than the diameter of the lower base plate portion 16 such that the cover member 30 may rest on the upper surface 19 of the lower base plate portion 16 the height of the protective cover member 30 is such that the stacking column cap 17 seats in the cover member hub 32 when the bottom rim of the cover member 30 is resting on the lower base plate portion 16 the inner diameter of the hub 32 is slightly larger that that of the stacking column cap 17 such that the cover member 30 may be freely rotated while resting on the lower base plate portion 16 the rotation index markings 35 are spaced uniformly around the lower edge 37 of the cylinder 33 of the cover member 30 and span the range of disc medium indexing angles 26 for all modified disc media 20 a 20 b 20 c etc in the stack 21 the rotation index markings are spaced at the disk increment angle as discussed above the disc lift mechanisms are disc lifting tabs 31 thin rectangular tabs spaced uniformly around the lower edge 37 of the cover member 30 and extend radially inward the number of disc lifting tabs 31 is the same as the number of outer disc notches 22 their length and width is such that they fit into the outer disc notches 22 of a modified disc medium 20 as shown in fig5 a through 5e to retrieve a particular disc of interest 62 from the.