What is UC# in cataloguing? KM finished?

Hi Team,

Sometimes for newer coins (2015+) on Numista there is no catalogue number. But then on other sources the same coin is labeled with a "UC#".

Has the Krause (KM#) cataloguing series finished, and UC# is taking over?

UC seems to stand for Uncatalogued; so perhaps modern coins that have not been added into the Krause 2001- catalog yet? This is just my guess.

Is that to say that they will eventually have a KM#?

In that case, I should stop writing the UC# on my 2x2's!