May also refer to The collection of PHP_CodeSniffer rules (sniffs) used to format and validate PHP code developed for WordPress according to the PHP coding standards. have stood as a beacon of hope, a promise that code written for WordPress will be easily readable, recognisable, and portable. Sadly, WordPress’ own PHP The web scripting language in which WordPress is primarily architected. WordPress requires PHP 5.6.20 or higher hasn’t lived up to that promise.
Weighing in at a respectable 105,650 lines added, 77,558 lines removed, with an 11MB diff,  fixes 94.8% of the coding standards issues in WordPress’ PHP.
The remaining 5% of coding standards issues require manual intervention, which means that we’re going to start accepting coding standards patches in the near future. Please hold off on creating tickets and submitting patches for now, while we figure out the best way to manage it.
Unfortunately, this change means that most patches currently on Trac An open source project by Edgewall Software that serves as a bug tracker and project management tool for WordPress. will no longer apply cleanly – they’re going to need updating. It’s going to take a bit of experimenting to figure out the most efficient way to handle this, if you’re interested in this problem, please go ahead and experiment!
The Wider Ecosystem
In the process of preparing for this, there were a lot of bugs fixed and features implemented in WPCS The collection of PHP_CodeSniffer rules (sniffs) used to format and validate PHP code developed for WordPress according to the WordPress Coding Standards.