Golem Damage Reduction

[Jhulae]

Is a Golem's (or any other monster's) damage reduction (Su), (Ex) or Natural Ability?

Since Golems don't have either (Su) or (Ex) qualities listed after it, according to the RAW, it appears to be a Natural Ability, correct?

 

[Shin Okada]

Official MM errata has an entry for DR.

Damage Reduction
Damage Reduction is either extraordinary (Ex) or supernatural (Su). Use the following guidelines if it is not specified.
● DR X/slashing, piercing, or bludgeoning should be (Ex)
● DR X/adamantine should be (Ex)
● DR X/-- should be (Ex)
● DR X/silver or cold iron should be (Su)
● DR X/magic should be (Su)
● DR X/chaotic, lawful, holy, or unholy should be (Su)

So Golem's DR X/Adamantine is (EX).

 

[Jhulae]

Exactly what I needed.

Thanks much!