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 and the Primary Administrator role are examples of privileged users. The sticky bit prevents a user from deleting other users' files from public directories such as /tmp:
drwxrwxrwt 7 root sys 400 Sep 3 13:37 tmp
Be sure to set the sticky bit manually when you set up a public directory on a TMPFS file system. For instructions, see Example 6–5.