Scott Catalog Numbering For US Commemorative Panes

For some sheets / panes of U.S. commemoratives which contain stamps of different designs Scott assigns a distinct catalog number for each stamp. For others Scott assigns a single catalog number for the set and a letter designation for each distinctive stamp.

I used to assume that the letter distinction was used when the different stamps of a pane together formed an image, such as with the pane of 10 "Nature of America: Hawaiian Rain Forest", Scott Number 4474 a - j issued 9/1/2010. But the pane of 12 "Modern Art in America", Scott Number 4748 a - l issued 3/7/2013 and the pane of 12 "Made in America: Building a Nation" Scott Number 4801 a – l follow this same convention.

Then there is the sheet (with two block of 8 sets) "Vintage Circus Posters" Scott Numbers 4898 – 4905 issued 5/5/2014 and the strip of 4 "Farmers Market" Scott Numbers 4912 – 4915 issued 8/7/2014 where each stamp is assigned its own Scott number.

There may be an obvious explanation but it is alluding me.

I most cases if the sheet has all different designs and only used once they will assign a major number to the sheet. The singles will be a,b,c,d,etc. The sheet of 10 Wildlife is an example.

If the design repeats, then they stamps are issues major numbers and the sheet is not.

I think the previous post provides the now obvious explanation … if a pane consists of all different designs, the pane is assigned the major number & each individual stamp a minor number (with an appended letter suffix). Otherwise, the individual stamps get the major numbers while the smallest block containing all the designs is assigned a minor number. The single exception to this rule seems to be when the pane is a "booklet". E.g., 5125a is the 2016 Pets double-sided booklet pane while 5106 thru 5125 are the 20 individual stamps from the booklet pane.

Thank you angore and JLLebbert, that makes sense now.

I think the real answer is Scott is not consistent in its numbering system.

Sometimes stamps in which every stamp is different, and which there is no overall design gives each stamp a individual number

Scott #4033-4072
Scott #4825-4844
Scott #5069-5070


Sometimes they do not
Scott #3351
Scott #3944
Scott #4524
Scott 5079

Or why are there different Scott numbers for Scott #3209h and 3210 and not Scott #4694-4697 and the four issued together on one sheet?