This document specifies how to extend the ISO 32000-2 specification by adding the ISO/IEC 12113 (glTF) format as a valid format for 3D artworks contained in a RichMedia annotation. It is intended for: • developers of software that creates PDF files (PDF writers); • software that reads existing PDF files and usually interprets their contents for display (PDF readers); • software that reads and displays PDF content and interacts with the computer users to possibly modify and save the PDF file (PDF processors); • PDF products that read and/or write PDF files for a variety of other purposes (PDF processors). NOTE – PDF writers and PDF readers are more specialised classifications of PDF processors. This document does not specify the following: • specific processes for converting paper or electronic documents to the PDF file format; • specific technical design, user interface implementation, or operational details of rendering; • specific physical methods of storing these documents such as media and storage conditions; • methods for validating the conformance of PDF files or PDF processors; • required computer hardware and/or operating system.