As far as I know, Basenotes does not have and chooses not to use such a system.
I recall reading posts in the past about this. Grant himself may have contributed, I don't remember. The gist was that there are no standardized fragrance categories and no standard system in use within the industry. I suppose the most widely used system might be the one used by Michael Edwards.
The placement of fragrances into various categories is subjective and highly flexible, especially with some perfumers now blending elements of different traditional categories to create "hybrid" scents. I think Basenotes wants to stay away from such arbitrary and subjective classifications.
I don't mean to speak for Basenotes, but that is my understanding.
But I do think that some sort of "similar perfumes" or "if you like this you might like that" feature might be useful to the community as a whole.