2013

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
a Control option or a single step of the UNDO command is available when
the One option is in effect.
Combine Controls whether multiple, consecutive zoom and pan commands
are combined as a single operation for undo and redo operations.
NOTE Pan and zoom commands that are started from the menu are not combined,
and always remain separate actions.
Layer Controls whether the layer dialog operations are combined as a single
undo operation.
Begin, End
Groups a sequence of actions into a set. After you enter the Begin option, all
subsequent actions become part of this set until you use the End option.
Entering undo begin while a group is already active ends the current set and
begins a new one. UNDO and U treat grouped actions as a single action.
If you enter undo begin without undo end, using the Number option
undoes the specified number of commands but does not back up past the
begin point. If you want to go back to before the begin point, you must use
the End option, even if the set is empty. The same applies to the U command.
A mark placed by the Mark option disappears inside an UNDO group.
Mark, Back
Mark places a mark in the undo information. Back undoes all the work done
back to this mark. If you undo one operation at a time, you are informed when
you reach the mark.
1126 | Chapter 2 Commands