Quite the contrary - if you removed the words "referred to by the term," the sentence would cease to make sense at all.
Just reading it alone, I can tell that this sentence is from the middle of a paragraph (again, otherwise it wouldn't make sense). The preceding sentence introduced a word or a phrase. This sentence expands on the idea previously introduced and is saying something additional about the word or phrase (basically that it's easy to pick out examples of that word or phrase, but it is hard to create a classification system for them)
Unfortunately, I can't find the original context for this sentence. All I can find is what seems to be some translation exercise, all of which have various levels of context (and because of that, the sentence stops being sensical.)