A Speech can be locked, preventing any changes to the Speech name, category, and settings. Only the user who locked a Speech can unlock it.
Locking a Speech is primarily useful as a way to restrict users to whom you have shared a Speech from making changes to it after they have downloaded it.
Imagine a scenario in which a professor creates a Speech named "Midterm Test", imports specific Speech Items, and chooses a standing teleprompter, projector, utility tool, and mic in the Small Hotel Conference Room. The professor then locks the Speech before sharing it with all of her students. When each student downloads the shared "Midterm Test" Speech, they will receive it with the settings chosen by the professor. Further, they will be unable to change those settings, because they are unable to unlock the Speech.
If the professor decides later that they want to update a Speech Item, they can unlock the Speech, update the item(s), then lock it again. Any students who had already downloaded the "Midterm Test" Speech would need to re-download the newly altered one.