You might want to configure macro definitions so they can be indented like program code for easier reading; see §28.1.1.4 Managing line breaks in macro definitions:
; Ignore macro linebreaks and subsequent leading whitespace,
; to allow indenting complex macro definitions:
Note: This setting is crucial if you want to use leading spaces in Mif2Go macro definitions, as in the examples in §14.8.2 Defining macros to process index content.