This post originally recommended http://schema.org/ (HTTP) based on reasons outlined below. It sparked exactly the discussion we hoped for: a structured conversation with stakeholders from NDE, CLARIAH, ODISSEI, and heritage institutions. On 2 April 2026, participants reached consensus on https://schema.org/ (HTTPS). We acknowledge that this recommendation goes against one of the core principles of linked data – cool URIs don’t change – but force of circumstance and pragmatic considerations have led us to advise HTTPS for Schema.org metadata going forward. This post has been updated to reflect that decision – see the recommendation.