Once you have selected a command, you are likely to use it several times before moving on to another command. That is how most people use tools; you pick up a tool, do several things with it, then pick up another tool, and so on. To avoid picking up the tool before each use, AutoCAD provides a command repetition capability, triggered by a null response. However, you cannot use this feature to specify command options.
This feature makes it possible for you to repeat frequently used commands until you choose another command. If a macro begins with *^C^C immediately following the item label, the macro is saved in memory. Subsequent Command prompts are answered by that macro until it is terminated by ESC or by the selection of another macro.
Do not use ^C (Cancel) within a macro that begins with the string *^C^C; this cancels the macro repetition.
The following is an example of the repetitive, or modal, approach to command handling.
*^C^CSTRETCH Single Crossing
Macro repetition does not work for items in image tile menus.