Oh I see :)
Is there a way to make it work like a toggle ?
So you only press the key once ?

HI DesuDeus - you trigger it after you've placed some clines. It will mark the ones that you have already placed as not being temporary, so those ones will stay around after the current command exits instead of going away when the command ends.

You don't need to press it multiple times, you can just do it once before finishing any command where you have created some construction lines.

- Michael