Although much has been discovered and written to date this seems to be all over the place, bits and pieces are written on different blogs, group discussions and websites. For these reasons some people are still finding it confusing. I will add a couple of images here and try to put the information learned to date in one place.
We can start with the latest booklet printed by Walsall security Printers in gravure. This is the 2nd in the series of the Design Classic self adhesive booklets. Issue date 21st April 2009.
This booklet contains 2 x 1st-class special issue Mini stamps and 4 x 1st-class gold 2B. Looking at the security slits this has the Type II slits which have a separation cut (approx 1mm long) in the center of the arc both top and bottom.
Using Douglas Myalls information, the hidden code in the background text is C = ROYAL MCIL According to Myall the C stands for Custom.
If you look closely at the scan you can make out the cylinder numbers W1 repeated in the lower right corner. The Previous booklet in this series contained the Routmaster bus and Phone box stamps. A further booklet, number 3 in the series (Concorde) is planned for early next year.
Now that we have that out of the way I will return to the security retail booklets that were issued earlier. Philatelic issue date 31st March 2009. First is the 12 x 1st-class gold 2B security booklet. To date cylinders W5 W1 / W1 have been identified.The security slits has the Type IIA slits which have a separation cut (approx 2mm long) in the center of the arc both top and bottom. thanks to Ian for the image (below left)
Code T. This means that the stamp came from a book of twelve. There are two of these booklets x twelve with type 11A slits, the second is again printed by Walsall. 12 x 2nd-class blue CB security stamps. cylinder booklets W4 W1 / W2 have been identified.
I will now turn our attention to the 6 x 1st-class gold 2B security booklets. There is only one book to describe which denoted Deegam Code S. = ROYAL MSIL. This indicates that the stamp came from a book of six definitives. Again printed by Walsall with type 2 (narrow) security cuts.
Next on the agenda are the 4 x 1st-class Large gold 2B security booklets, both first and second class booklets were issued they contain Code F. = FOYAL MAIL. Click here and Click here for details written by Larry of the hidden text
This indicates that the source is a book of four stamps. Cylinder booklets on both 1st and 2nd class booklets known to date are W1 W1 / W1. Looking at the security slits this has the Type II slits which have a separation cut in the arcs (approx 1mm long). Again thanks go to Ian for this image (left)
The business sheets mentioned on an earlier Post have Type I slits which have no separation cut in the center of the arcs. Using Douglas Myalls codes, the hidden code in the background text is type Code B.
This B indicates that the source is a business sheet, printed by De La Rue with type 1 security cuts, ( no gap in the arc) again first issued on 31 March 2009. The position of the B depends on whether the stamp is standard or large.Douglas Myall describes these as:
B replacing A of Mail, sheets of 100, 1st class standard and 2nd class standard
B replacing A of Royal, sheets of 50, 1st class large and 2nd class large.
With this post I have tried to make this information idiot proof, which is difficult considering the amount of text to take in. I have also given links to previous posts, sorry if this is confusing but I have only done this so I do not write the same info twice. Any mistakes please let me know.