Booting an Ubuntu DVD, pressing F6 and then ESC presents the boot prompt with the default kernel options, with the possibility of editing and adding extra options. Something like:

kernel /casper/vmlinuz boot=casper quiet splash --

Questions:

1. What's the meaning of the two hyphens?
2. When adding an extra option (such as "toram" or "vga=791"), is there any difference between adding it BEFORE or AFTER the hyphens?

When typing commands in Bash, two hyphens in a row means "options end here; anything that follows should be treated as an argument, even if it starts with a hyphen". But the hyphens must have another meaning at the boot prompt, as "toram" or "vga=791" really are options.