In the millennial web forum world, a n00b would ask "what does $| do?" and the answer would be "it disables output buffering", which is what the n00b wanted to know in the first place. It's the Stack Overflow model of giving men fish, instead of teaching them how to fish.
And in today's LLM-powered world that's only more true. If you ask ChatGPT "In a Perl script, what does $|++ do?" it will immediately give you a correct and concise answer, not make you read `man perldoc` first.