1.Modifies all files in the current working directory so that they can be deleted.
2.Changes the directory date to 1777; commonly used by hackers to cover changes. Lets any user delete the files, but not create new ones.
3.Freezes all files in the current working directory so that they cannot be modified.
4.Sets the permissions on the current working directory to rwxrwxrwt on a Unix filesystem.