Not so long ago I have noticed that there exists nested-radicals tag. (It is still listed among new tags so it cannot be very old. It was probably created in this question. At least it was the oldest question, which had that tag at this moment at the time I saw it for the first time.)
Will we keep the tag? (In that case, there are several old question where this tag can be reasonably added. I have already added this tag to several questions.)
Or would better solution be to make it synonym of sequences-and-series? Or is it some better choice of a synonym?