DCL implements command line editing and recall, so that users can more easily correct typing errors and reuse previous command lines.
Recall buffer: access to recently issued commands
$ RECALL string Bring up last command beginning with string.
$ RECALL/ALL Displays all commands and their numbers.
$ RECALL number Use a number found in RECALL/ALL.
Command line editing (if it isn’t on, do: $ SET TERM/LINE):
$ {up-arrow} Previous command in recall buffer.
$ {down-arrow} Next command in recall buffer.
$ {Ctrl A} Toggle insert/overstrike editing.
$ {Ctrl D} Move one character left.
$ {Ctrl E} Move to the end of the line.
$ {Ctrl F} Move one character right.
$ {Ctrl H} Move to the beginning of the line.
$ {Ctrl J} Delete word left of cursor.
$ {Ctrl R} Rewrite the command line.
$ {Ctrl U} Delete line left of cursor.
$ {Ctrl X} Cancel the current command line.
Miscellaneous:
$ {Ctrl 3} ASCII code for {Esc}.
$ {Ctrl I} ASCII code for {Tab}.
$ {Ctrl Z} Tell DCL "end of file". Used in some programs
to indicate more general sorts of "end" commands.
Of these, only {Ctrl I} will insert a character into the command line, rather than just move the cursor around. No new characters may be inserted before a tab ({Ctrl I}) in a command line, but existing characters may be changed in overstrike mode, or deleted. This behavior is documented in the “I/O User’s Guide” and has existed since VMS 4.0.