From https://mail.kde.org/pipermail/tellico-users/2023-September/001842.html

I checked in recently and found that Tellico now has a Numista data source. This is great! However, it seems that the Numista search method Tellico uses does not use Numista's N#'s. This is a unique number assigned to everything on Numista.  There are also NN#'s for subtypes.

I have tried repeatedly with multiple different search terms, but I have yet to be able to use the Numista search in Tellico to find a 2 US Dollar note. I was able to browse to it on the Numista website. So I have the URL (https://en.numista.com/catalogue/note201812.html), the N# (N# 201812; also in the URL), the description... but I cannot get it into Tellico bc Numista's search is so horrible.  (by the way, the search results seem to be limited to 20 items)

IDEALLY, I'd hope to be able to use Tellico to do a straight lookup by both
1) URL of the item, which contains type (banknote, coin, exonumia) and N# in it (this will be important later)
2) The N# or NN# directly

Per the API docs (https://en.numista.com/api/doc/index.php) it seems that N# lookups are straightforward, you just need to know the type:  https://api.numista.com/api/v3/coins/95420
Because of that, the Tellico Numista search dropdown might need to add "Coin N#", "Banknote N#", and "Exonumia N#" options.