A macro is a series of commands that executes specific actions when a toolbar item is selected. Macros can simply be recordings of keystrokes that accomplish a task, or they can be a complex combination of commands, AutoLISP, DIESEL, or ActiveX programming code.
If you intend to include command parameters in a menu macro, you must know the sequence in which that command expects its parameters. Every character in a menu macro is significant, even the blank spaces. As AutoCAD is revised and enhanced, the sequence of prompts for various commands (and sometimes even the command names) might change. Therefore, your custom menus might require minor changes when you upgrade to a new release of AutoCAD.
When command input comes from a menu item, the settings of the PICKADD and PICKAUTO system variables are assumed to be 1 and 0, respectively. This preserves compatibility with previous releases of AutoCAD and makes customization easier because you are not required to check the settings of these variables.