For the Australian blank base 5/- stamp the “S Flaw” is cited as BW D11e, with the footnote that the flaw is “believed to be a primary flaw”. Unfortunately, I could find no definition in the BW catalogue detailing what the Editor of ACSC 2020 meant by a primary flaw. As we have seen, in the Hyeronimus classification of flaws a Primary Flaw is one which occurs in each stamp of a given column ie 10 stamps in each of the right and left panes. I personally don’t think it is a primary flaw by that definition.
As with earlier stamps, the difference in the N.S.W. residual blank markings strongly indicates that the 2 blank base stamps are not from the same sheet position.
I note for the record that there is no listing of the flaw for NSW 5/- postage due stamps. But as can be seen in the above scan they clearly exist. Again, as with all these flaws, a full sheet is needed to settle sheet position and number of occurrences questions.
The watermark on the NSW stamp with the upper case SPECIMEN overprint shows it came from a column 1 position.
Postage Due Stamps 