Coding_guidelines

Postfixadmin doesn't have a tons of papers describing coding guidelines ;-). It's recently migrated to PSR2 via PHPCS ( See: https://github.com/postfixadmin/postfixadmin/commit/15df6c1d7b5b1e254a9e478fca21de2b13a704b0 etc).

Code however you want to, then run 'composer check-format' ...