(registered 2026-08-12, last updated 2026-08-12) Media type name: application Media subtype name: vnd.prismatic Required parameters: N/A Optional parameters: N/A Encoding considerations: 8bit Security considerations: A .prsm file is a valid HTML document and inherits all security considerations applicable to HTML (cross-site scripting, resource loading, etc.) when rendered in a browser context. Image data is embedded as RFC 2397 base64 data URLs and is not executed. The manifest JSON is embedded in a