Roblox is rolling out an age verification feature that will allow players to confirm their age and gain access to features reserved for older players. Age verification will be optional, and Roblox tells The Verge it will “not retain any data” from the verification process, which requires showing a form of ID.

For now, only one feature requires age verification: Roblox’s new voice chat feature, Spacial Voice. During its initial beta test, it will only be available to players who verify they are at least 13 years old. (Roblox didn’t say whether it would later be available to users regardless of verification status.)

But the implication seems to be that other features — perhaps specific Roblox games or community tools — could be age-gated as the company works to protect its relatively young user base. More than half of Roblox’s users are still under 13 (Roblox says “nearly 50 percent” were over 13 as of the second quarter of the year).

Verification will require uploading an “ID card, driver’s license, or passport” as well as a selfie taken “on the spot” to help confirm that the ID was really uploaded by the person to whom it belongs. Roblox only accepts government-issued IDs, which could pose a problem — younger players are less likely to have formal IDs than older players, and that’s likely even less common in certain regions where an ID is harder to obtain.

The feature starts rolling out today and will be available globally to users who are at least 13 years old.

Correction September 21st, 4:05PM ET: “Nearly” half of Roblox’s users are now over 13; this story initially said more than half were over 13.