Moderators (of residences and shops) no longer have the option of locking threads. IC threads should never be locked. Important/relevant descriptions should be pinned. If it's pinned it does not also need to be locked.
To signify your character leaving a thread/scene, in addition to the actual post, at the end put: </Exit *insert character's name*>
To signify the end of a thread/scene the last poster should put: </End Scene> at the end of their post.
OR once a thread is concluded the maker of the thread can change the subtitle to Read Only or Closed.
If you forget to do that then you can always ask an Admin/Mod to do it for you.
Where were you when I laid the foundation of the Earth?