goals: system wide
Consistent conventions and abbreviations throughout a codebase take on a life of their own. The reader learns it as shorthand.
Conversely, multiple convention sets causes duplication and over-commenting, undercutting the jump to arcology.
A project-wide included file is a place for shared style. It's an important document and should be required reading!
A large project requiring multiple includes should keep them in strict hierarchy. Because of their omnipresence, this is an area where vigilant organization really pays off.
nedwaves.com 2017