Files that are checked out to you have a lit lightbulb icon. Check out a page to prevent others from entering conflicting changes while you are working. Click the lightbulb icon to check a file in or out.
Files that are checked out to another user have a red lock icon. If a file is locked to someone else, you cannot edit it. The exception is for administrators, who can forcibly check the file back in. If a file someone else is working on is forcibly checked in, their unsaved changes will be lost. If you hover your cursor over the lock icon, you can see which user has the page checked out.
Files that are scheduled to publish have a calendar icon.
Files that are scheduled to expire have a "No" icon.
Files that are pending approval as part of a workflow have a silhouette icon.
