The whole draft is in good shape and well written. Some nits: 1. every word should start with capital letter for the section title; 2. section 2.2.4: / ceil(a) the largest integer less than or equal to a / ceil(a) the smallest integer larger than or equal to a / 3. section 3.7.2: [ISO.15444-1.2016]? 4. section 12.1: [I-D.ietf-cellar-ffv1]? 5. section 12.2: should all the RFC move to the Normative References (section 12.1)? Issues for clarification: In Security Considerations, besides the DoS attacks brought by the malicious payloads, is there any other kinds of attack possibly? For example, virus or worm are hidden in the malicious payloads to attack the system for more damages? Does it make sense and what's the consideration?