I list a ridiculous 412 of these. Things started well enough in 1989 with an attractive pair -
With booklets, self adhesives and every printer getting involved at some point the NVIs exploded. We had an E value and now have airmail and Worldwide items as well as Recorded Signed For and Special Delivery labels.
At one point I thought all was lost when a horrid design with a fat numeral emerged in connection with PIP. Although the 1st Large has continued the ugly normal size exited stage left after a year.
There are some interesting items, including the three horizontal format ones from 1993 and 1997 and one or two others. Regionals, PB150 and Wildings are in their own lists.
Just as we thought it was safe to leave just a few blank spaces, along come ‘Security Issues’ with more than elliptical bits in the perforation now. This time we have even more difficult words to spell, like iridescence and fluor seems to appear more than it did before. There’s a layer over the stamp which spells Royal Mail or occasionally something else and that something else tells us the source of the stamp and a printing year. So we need to look out for things like MCIL M12L and then maybe the same item but with M13L a year later.
There have also been short term issues to mark the Coronation in 2012 and Her Majesty becoming the longest reigning British monarch in 2015.