Automatically generate a "ND value"

Hello,
I noticed some people only collect per type and don't bother to check the year or variant of their coins : when they enter their collection in Numista, they just chose the first lines of every pages they came across.
Meanwhile, sometimes we can clearly identify a type of coin, but some informations such the mint, the year or the variant can't be determined due to its condition or the way it was minted (some parts of the die are often missing on hammered coins).
Those points can create some confusions during an exchange and even modify the value of a coin when people randomly chose a variant.

Those informations may appear useless for some users, but for people who collect per year, variant, hammered coins or coins written in foreign scripts, those values are important to know.

It's the reason why I propose to automatically generate a "ND" value with a comment "variant / year undetermined" (or something like that) when there is more than two entries in the catalog for a single coin.
This new value would appear on the first line of the year list and use the lowest and highest value of the years that have been added.

Hello,
This idea is already tracked here: https://en.numista.com/forum/topic44653.html