Once a macro has been added to the Macros.xml in your Active 4D directory, those macros will also be available to be "auto-completed" from the Method editor. However, the macro being auto-completed actually executes the macro.

For example, the CodeModif macro is a default macro automatically added to the Macros.xml file. From the Method editor, typing CodeMod results in the macro being executed when it is auto-completed.