please explain remove_from_list

i am using acts_as_list on one of my models and was looking at the
different methods available for it. i saw remove_from_list and tried it
out, but it doesn't seem to work. i don't know if i'm not doing it
right, or if it just doesn't do what i thought it would do.

i basically just want to take a record and do exactly what it says...
remove it from the list. when i called the method i was either
expecting the position to either change or be null, but i don't think
it did either.

could someone please explain how to use this and what it does to my
data?