Debian policy manual? What Debian policy manual?

Danger, Will Robinson! Don't try ANY of this at home! We're what you call dangerseeking airheads, and WE'RE NOT RESPONSIBLE!

It's here, stupid, and you need it to start and stop daemons (such as Apache 2.28's httpd, if like me you installed from Apache's own source code) neat, sweet 'n automatic.

The gist is, your daemon control scripts (see /etc/init.d/skeleton) are in /etc/init.d and then there's a battery of directories called /etc/rc0.d, rc1.d, ..., rc6.d which contain symbolic links back to your daemon control script, with implicit instructions to start or stop the daemon based on the name of the symbolic link. These six correspond to Ubuntu runlevels; e.g., 0 is boot time, 1 is single-user maintenance mode, 2-5 are all graphical user levels under Ubuntu, and 6 is reboot.

Danger, Will Robinson! Don't try ANY of this at home! We're what you call dangerseeking stupidheads, and WE'RE LIKE TOTALLY IRRESPONSIBLE, DUDES!!

K20daemoncontrollerscript means call /etc/init.d/daemoncontrollerscript stop, while S21daemoncontrollerscript means call /etc/init.d/daemoncontrollerscript start. The two-digit numbers represent call order relative to the other stuff in that particular directory. Note in particular how /etc/init.d/rc.local is called, and where from. If you have mysql or postgresql installed, these also may provide much food for thought.

Note: There is also an /etc/rcS.d. It works the same way, but dork with the contents at your peril. It's what determines whether your system is ready for everything (or anything) else.

Danger, Will Robinson! Don't try ANY of this at home! We're what you call dangerseeking heronpluckers, so KWAI SHR BI CHEN!!!

Note: The hidden peril in all this is not that you've compiled your own preferred version of the source, but the fact that you've ignored (or never knew about) package dependency information for everything else that may depend on what you just installed. See the policy link, above.