Apart from installing a macro, how can I make a macro file to appear listed in the Plugins menu?

Include an underscore “_” in the macro name and save it in the Plugins folder (or one folder below). After re-starting ImageJ, the macro name will appear in the Plugins menu, with the underscore character converted into a space.

For example, MyMacro.txt will not appear in the menu, but My_Macro.txt and Macro_.txt will be listed as “My Macro” and “Macro” respectively.