Code changes,
in the language of the field.

Code books are written to be legally precise, not readable. When a new edition lands, most of it looks like the last one until you hit the sections that quietly changed and cost you a re-inspection.

These guides pull out the changes that actually affect how you work: what moved, what it means on a real installation, and where inspectors are writing people up.

Always verify against the edition your AHJ has adopted. Adoption lags publication, sometimes by years, and the code in force is the only code that matters.