"As with base backups, the easiest way to produce a standalone hot backup is to use the pg_basebackup tool. If you include the -X parameter when calling it, all the write-ahead log required to use the backup will be included in the backup automatically, and no special action is required to restore the backup."
This makes it sound like -X is a switch option, when in fact it demands an argument. The statement made is incorrect if the supplied argument is "none", but is correct for the other two options. Should this be changed to spell out which options it applies to (or maybe which option it does not apply to).
Just reading the doc page for pg_basebackup: "stream" is the default method value for this option. So if you just include "-X" you get "stream" which is indeed a mode that just works and the continuous archiving section you quote is correct.
I'm not really sure I like the idea that we don't indicate which pg_basebackup key-value argument values are optional and which are mandatory.