The Philatelic Foundation has issued a certificate identifying a major error on RW35, the 1968 issue. The certificate states, “The inscription on the reverse has been omitted, bottom right plate number 170443 single.” A collector in the Northwest unearthed the missing writing stamp while sorting through his collection, and noticed it did not have an inscription like the others. The stamp was sent to me for examination, and I could find nothing that would disqualify it as a genuine back inscription omitted, so I submitted it to the Philatelic Foundation for their opinion. Federal duck stamp major errors are very rare, and seldom occur. A maximum of four million of each year were printed, and approximately 40%, or about 1.4 million actually sold in most years. Compare that to postage stamps which are typically printed in the hundreds of millions, and the chance of finding a duck stamp error greatly diminishes. Two other federal duck stamps, RW29 and RW57 have thus far been discovered and certified with the back inscription omitted. Detection is difficult, since regummed stamps in these years would not have the inscription, so original gum is vital. Back inscriptions first began being placed on federal duck stamps with RW13, but the printing was directly on the stamp, under the gum. That all changed with RW21. Beginning with this issue forward, all inscriptions were placed on top of the gum, so any tampering or removal of gum would also remove the inscription. The printing ink is integral to the gum, and cannot be removed completely without most of the gum being removed. If removal of only the inscription is attempted, it will smear into the gum and result in an obvious puddle of black muck. The gum on the discovery example is pristine, except for a minor area of disturbance and light hinge mark. Errors such as this are very rare indeed, and a commensurate value follows that rarity. When such an item becomes available, several serious collectors often bid through a dealer or agent. The right of ownership of the only known example is sometimes the difference in a winning or losing exhibit. Thus far, most examples of back inscription problems have occurred on the $2 and $3 duck stamps. For instance, RW22, RW24, and RW26 exist with the inscription inverted, and RW29 and RW35 have the inscription omitted. It’s interesting to note that most known errors of this type occurred in a 15-year period, until RW57 was discovered with the inscription omitted. Except for the latter error, there are only a few examples of these errors that have been discovered. Perhaps more exist for future lucky collectors to discover.