This site uses the youth protection label from JUSPROG.

“In Germany and Europe there is a technical standard for a youth protection label for the age classification of websites. The label age.xml /age-de.xml is officially established in Germany by the criteria for youth protection programs of the Commission for Youth Media Protection (KJM). It makes sense to integrate the label, JusProg has already integrated the age.xml and age-de.xml label into its filter software.

Many large and small website operators have already installed an age-de.xml label, including almost all private TV providers from RTL to Pro7 and Sky, many game portals, Youtube, bild.de, spiegel.tv, to name just a few of many to name examples, and also almost all state media authorities as well as various other state websites and all self-regulatory institutions.

In Germany, the age-de.xml label is mandatory according to § 11 JMStV for website operators who want to protect minors from the content of their website. The file age.xml applies internationally.”

For more information https://age-label.com/parents/
For Germany more information at https://jugendschutzprogramm.de/