I think the next bit from the article I didn't quote explains that:
"(2) Provide a developer who has requested a signal with respect to a particular user with a digital signal via a reasonably consistent real-time application programming interface that identifies, at a minimum, which of the following categories pertains to the user."
The categories are broken into four sections: users under 13 years of age, over 13 years of age under 16, at least 16 years of age and under 18, and "at least 18 years of age."
I think the idea is that you would say that under 16s can't use social media. Then you'd enforce this not with the horrendous Australian strategy of having everyone IDed, but instead you would enforce it by having an API that websites and apps could use that would tell them the age of the user.
So basically:
- Parent sets up device for kid and sets their age.
- Kid tries to download Facebook app
- Gets denied because they are under age
- Kid tries to go to facebook website instead
- Website sends request to browser for user's age, browser asks Windows (or whatever OS) for age and provides this age back to Facebook
- Facebook denies access because user is under age
Windows might already have parental controls within Windows, but it's the ability for apps and websites to know the age (or in this case age range) that is the important part.
I much prefer this than handing over ID.