What I have to say is that the fluorescent mark is absolutely fabulous. The whole sheet-of-20 is covered with images of small flying bird. However, not all the flying birds have word SPM beneath. The flying birds with SPM are arranged in such a way that SPM appears once in every 6 birds in a column and every 3 birds in a row. This makes only one SPM appearing in every single stamp. One more interesting thing is none of the flying birds on the sheet margins to have SPM! Fantastic!
On the MS, the flying birds are also covering the whole MS. However, only one SPM is present in the whole MS. The word SPM is located at the left bottom of the stamp. It is rather between birds than beneath bird.