certbot certonly --help produces incomplete output.
Let me know how to get actual dump of all certonly flags... I know there are many, because I'm using many flags which are missing from help message.
certbot --help certonly should give you the help for the certonly subcommand (note the order). Or you can use certbot --help all for everything.
certbot --help certonly
certbot --help all
This gets me what I was after... The docs for no-hsts...