1. ► ls --color is not a POSIX compliant option.
2. ► You cannot use a shell not listed in /etc/shells.
3. ► set and export do identical functions.
4. ► An user cannot change his/her finger information.
5. ► ksh, zsh and bash all extend sh.
6. ► PATH variable is common across shells.
7. ► /etc/password stores user password in plain text.
8. ► csh is an extended version of tcsh.
9. ► Login shells can only be started by the system at login time.
10. ► libtermcap makes use of /etc/termcap.