This feature is used to protect your files from being changed or removed by another users.
You can lock or unlock the file by clicking on the toolbar, or click → .
The icon is located next to the title of the locked file in the Workspace panel and at the title of this file tab in the Content panel.
Another users can open the locked files in the only-read format, but cannot edit, save, delete, move or rename them.
If you open the locked file with the WYSIWYG editor, you can edit its content, but the Save function is disabled.