It's mostly so I can immediately see which targets are phonies. Every phony has a line directly above it adding it to the list of phonies. When a makefile gets complex enough we need all the help we can get.

I use phony targets so much I wrote a shell script to parse the makefile database dump into some sort of help text. It doesn't depend on that variable at all.

https://github.com/matheusmoreira/.files/blob/master/~/.loca...

Prints output like:

  phony1
  phony2
          dependency1
          dependency2