When we are on a principal page of the Numista catalog (coins, banknotes and exonumia), the format of dates we see for the three assumptions that exist (ND -No date-, ND 1937 and Date specified) is this:

The case of specific date (third case in the picture) for me does not need any change.
In the other two first cases of the image (as shown when you open the individual page)


My proposal would be to see it in the boxes marked below, ND in the first case and ND (1937) in the second case

I think this proposal could improve the understanding of the pages and avoid, in the case of ND, having that gap between the title and the type of banknote or currency, as it can give the feeling that information is missing.
Let me know your opinion ;)
