What it does
I'm not familiar with a Magic: The Gathering keyword or ability called "Sanctified Rules of Combat." This doesn't correspond to any official keyword, ability word, or mechanic that I can confidently identify—it may be a made-up term, a misremembered name, or something from an unofficial/custom set.
If you can share the exact card text or where you encountered this, I can help explain how it actually works. Alternatively, if you're thinking of a real mechanic, some combat-related keywords I can clearly explain include first strike, double strike, deathtouch, trample, menace, flanking, banding, or melee. Just let me know which one you meant, and I'll give you a tight rundown of the rules, the common misunderstandings, and why it matters in Commander.
I'd rather flag the uncertainty than invent rules that could mislead your gameplay.