Note: Things noted to go through and read also are typically what's done both before/after and while code is supported as part of the process of producing production-grade code. aka testing is based on coding design specifications.

documentation (user, designer, programmer/coder, etc) outlines what can expect of code for a given code release without actually having use/look at the code.

open bsd is one example[0]

[1] : https://www.openbsdhandbook.com/