用於移除物件和更正錯誤的指令

指令

BREAK (指令)
BREAKATPOINT (指令)
CUTCLIP (指令)
ERASE (指令)
JOIN (指令)
LAYDEL (指令)
LAYMRG (指令)
MREDO (指令)
OOPS (指令)
OVERKILL (指令)
PURGE (指令)
PURGEAECDATA (指令)
REDO (指令)
REDRAW (指令)
UNDO (指令)

系統變數

COMMANDPREVIEW (系統變數)
UNDOCTL (系統變數)
UNDOMARKS (系統變數)