Emily Shaffer makes the case for commenting regular expressions.

It’s probably not a good idea to encourage your coworkers to think critically about what life would be like if you got hit by a bus, but the good news is that you can simultaneously document your regular expression and teach your coworkers some regex basics, if you comment them carefully!

https://nasamuffin.github.io/regex/documentation/2019/05/08/documenting-regex.html