debian sysV scripts adding to startup and removing from startup

I always forget following command.
Works on old sysV init type init system.
To add service into startup on nginx example:

# update-rc.d nginx defaults

to remove service from startup:

# update-rc.d -f nginx remove

https://www.debian-administration.org/article/28/Making_scripts_run_at_boot_time_with_Debian