As far as I know, when a group of people or things with particular features in common are classified we can use "fall into a category". But quite recently I came across the following sentence in a linguistics book published by Hodder Education:
Notice that these examples fall under well-established categories of acceptable, standard English.
There is no record of "fall under a category" in none of my learner's dictionaries. Instead, they all say "fall into a category". For example:
"Voters fall into three main categories."
"Students over 25 fall into a different category."
So, is "fall into" different from "fall under" when we talk about categories?