Modify file attributes. Specific to Linux Second and Third Extended Filesystem (ext2 and ext3). Behaves similarly to symbolic chmod, using +, -, and =. mode is in the form opcode attribute. See also lsattr.
Modify directories and their contents recursively.
Append only for writing. Can be set or cleared only by a privileged user.
Immutable. Can be set or cleared only by a privileged user.
Journalled file. This is useful only in cases where you are using an ext3 filesystem mounted with the data="ordered" or data="writeback" attributes. The data="journalled" option for the filesystem causes this operation to be performed for all files in the system and makes this option irrelevant.
Secure deletion. The contents are zeroed on deletion, and the file cannot be undeleted or recovered in any way.
Undeletable. This causes a file to be saved even after it has been deleted, so that a user can undelete it later.