From a scientific point of view, there is still no clear definition of what Ягель (Yagel) is. And probably never will be. In some works it is used for the whole genus Cladonia, in others it is used for all fruticose and foliose lichens growing in the tundra, in others it is said that these are all ground lichens in the forest-tundra.
A more or less clear definition of this word in Russian: Ягель (Yagel) is what the reindeer eats.
The moving of this folk name from one taxon to another is a little discouraging.
I don’t know how iNat’s naming system works, but is it possible to somehow block this name from being used? It misleads Russian-speaking users who do not understand lichens.
This is true. And if a person is really interested in the correct definition of the species, it is possible to open a description of the taxon, or refer to specialized literature. However, there are very few people who do this. And I’m not ready to become an iNat teacher. Simply, if we can avoid the occasional confusion then why not. Many Russian-speaking users remember the word Yagel from school as “Yagel is strange white or greenish tussocks of moss.” And seeing “a strange greenish tussock of moss” they immediately choose Yagel, not knowing or forgetting that Cladonia has more than 30 outwardly similar species like “Yagel”. And yes, I’m only talking about Cladonia, because many who are not interested in lichens are not aware that the “strange greenish tussocks” can be Cetraria, and white Flavocetraria.