http://www.gentoo.org/doc/en/rc-scripts.xml explains that 'need' is a strong dependency between services, and that 'use' is a weak dependency that will affect the order in which services are started if they are added to the same run level. Today I was suprised to discover that 'use' does not affect the order in which services get *shut* *down*. 'need' does affect shutdown order, but this is not explicitly mentioned in the guide either. I think it would be useful if it did.
I'm currently rewriting the Init-specific parts, so I'll handle this one.
The part on USE flags in the second part of the handbook states: """ Note: Only the services that need the given service are stopped or restarted. The other depending services (those that use the service but don't need it) are left untouched. """ This is when "/etc/init.d/<service> stop|restart" is being discussed.