| apropos | Locates commands by keyword lookup. |
| cal | Displays a calendar. |
| calendar | Writes reminder messages to standard output. |
| factor | Factors a number. |
| help | Provides help information for new users. |
| learn | Provides computer-aided instruction courses and practice for using files, editors, macros, and other features. |
| leave | Provides reminder messages. |
| units | Converts units in one measure to equivalent units in another measure. |
| write | Sends messages to other users on the system. |
Chapter 9, File and System Security
Chapter 2, User Environment and System Information