A locked choice has a padlock to it, and it looks like something like this:
See the last choice there?
You can use it when you don’t want the reader to select that option-it is locked for them. However, even if a locked choice is in your story, the reader can still get past through it unless you write up a code to prevent them from going further.
Example:
label customize_hair01
NARR
Pick yourself a hair color.
choice
< LOCKED>“Pink” {
NARR
Unfortunately, you can’t select for your hair to be pink until much later in the story.
goto customize_hair01
}“Black”{
NARR
Bla, bla, bla, the scene where you change you hair to black goes here.
}
#continue writing the script
So…as you can see this is just a simple example of a locked choice but it would go something like this and it can be used in other ways, too, like remembering a past choice and seeing if the reader unlocked a scene or not in the future : )
I hope this helped xoxo 
