Sorry for the confusion. I didn’t mean to suggest the post violated the rules; I was only trying to request more information (my comment was the second in this thread—no one had posted a summary or workaround at the time).
Thanks to everyone who summarized or referred me elsewhere.
This is in the FAQ at https://news.ycombinator.com/newsfaq.html and there's more explanation here:
https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...
https://news.ycombinator.com/item?id=10178989