Sticky Bit

The sticky bit is a permission bit that protects the files within a directory. If the directory has the sticky bit set, a file can be deleted only by the file owner, the directory owner, or by a privileged user. The root user is an example of a privileged user. The sticky bit prevents a user from deleting other users' files from public directories such as /tmp:

drwxrwxrwt 74  root  sys   18K Sep  7 17:07 tmp

Be sure to set the sticky bit manually when you create a swap file or set up a public directory on a TMPFS file system. For instructions, see Setting Special File Permissions in Absolute Mode.