DR presentation question [3.5+PF)

[Teapot Salty]

hey guys. So when looking at dr, I notice that it is often presented in a way resembling DR 5/good, now correct me if I'm wrong, but is that essentially meaning that you gain the bonuses of DR, except against good? Or is it only against good? Thanks, and as always, go nuts.

[torrasque666]

Nail on the head.

Specifically, you have Damage Reduction, but good-aligned weapons(whether through spells, enhancements or class features) ignore the Damage Reduction.