When trying to make a private homebrew human variant I was attempting to give it a version of the Changeling Instinct racial feature and realized that the “Choose a Changeling Skill” subtype is not there for the Proficiency Modifier.

Have you bought the CHangeling race or Eberron book?

I find many race-depending subtypes only show if you unlocked it on your account.

Quote from Cyb3rM1nd >>

Have you bought the CHangeling race or Eberron book?

I find many race-depending subtypes only show if you unlocked it on your account.

 Yes, I have purchased Eberron. I figured out how the Changeling worked by making a race based off of it to see how DDB did it. I mean, it’s me Cyb3r.

I did find that the exact same options are available if I use the “choose a telepathic skill” modifier subtype so I guess it’s irrelevant. Sorry.