beastie 5.X boot menu

[bob at a1poweruser.com]

The boot menu has changed between 4.x and 5.x releases. I have
searched the handbook and can not find any written documentation
about the new beastie boot options, what they are and when each one
is intended to be used. I see a lot of posts about the beastie
figure but nothing about what the options mean.  If it's written
somewhere can someone point me to it and if not can I get an
explanation?