2011

Summary
UNDO displays the command or system variable name at the Command
prompt to indicate that you have stepped past the point where the command
was used.
NOTE UNDO has no effect on some commands and system variables, including
those that open, close, or save a window or a drawing, display information, change
the graphics display, regenerate the drawing, or export the drawing in a different
format.
List of Prompts
The following prompts are displayed.
Enter the
number on page 1995 of operations to undo or [Auto on page
1995/
Control on page 1995/BEgin/End on page 1996/Mark/Back on page 1996]: Enter
a positive number, enter an option, or press Enter to undo a single operation
Number
Undoes the specified number of preceding operations. The effect is the same
as entering u multiple times.
Auto
Groups the commands in a macro, such as a menu macro, into a single action,
making them reversible by a single U command.
UNDO Auto is not available if the Control option has turned off or limited
the UNDO feature.
Control
Limits or turns off UNDO.
All Turns on the full UNDO command.
None Turns off the U and UNDO commands and discards any UNDO
command information saved earlier in the editing session. The Undo button
on the Standard toolbar is unavailable.
The Auto, Begin, and Mark options are not available when None or One is in
effect. If you attempt to use UNDO while it is turned off, the following prompt
is displayed:
Enter an UNDO control option [All/None/One/Combine/Layer] <All>:
One Limits UNDO to a single operation.
The Auto, Begin, and Mark options are not available when None or One is in
effect. The main prompt for the UNDO command changes to show that only
UNDO | 1995