When you enter commands, they are  first  processed  by  a  utility  that   
enables history, aliases, and other features.                               
                                                                            
For help on aliasing, see "help alias", also see "help history".            
                                                                            
Here is a list of other features:                                           
                                                                            
Command issued           Effect.                                            
^sub^stit                The string "sub" is replaced by "stit" in the      
                         previous command, then executed.                   
<cmd>\                   <cmd> is stored, and appended with the next        
                         command issued. Unless the environmental           
                         variable "no_build" is set.                        
~?                       Print help in command building mode.               
%%                       Repeat previous command.                           
%<num>                  Repeat <num>'th last command.                      
%<num>                   Repeat <num>'th command in history list.           
%<num>^sub^stit          History substitution.                              
%<string>                Repeat last command beginning with <string>.       
                         (See "help history").