CodeIgniter Style Guide
This is collectively being called a style guide, however it serves as a standard to enforce a stricter and more enforced methodology in how programming should be done in CodeIgniter.
CodeIgniter is powerful. CodeIgniter is hugely popular. It's popular because it's easy. It's easy because there are many ways to accomplish a task.
CodeIgniter is terrible for the exact reasons which make it powerful. You can too easily place code in a confusing place, or not separate concerns, thus creating programming challenges down the line. It's noob-friendly, which means it's inherently easy to make noob mistakes.
This document serves to restrict coding practices within CodeIgniter with the purpose of making an application with more class (pun without-a-doubt, most-strongly intended).