It appears that one could save up to 22 bytes of program-space by carefully considering whether you really need *both* initialized *and* "uninitialized" global/static variables... Choose one method for the entirety of your project and you might save a few bytes!

https://hackaday.io/project/18574-limited-code-hackstips/log/49537-avr-project-doing-nada-58bytes-and-some-experimentsresults