Code review: obey styleguide, understand before changing

The styleguide rule doesn't need approval since it's already stated in the styleguide document, but I referenced it here since it's relevant.

The "don't understand" bit is new, though. I would guess no one disagrees with that thought but I'd at least like everyone to read through it before we merge.

- [ ] HN
- [ ] KP
- [ ] AR
- [ ] JK
- [ ] TS