This document specifies how a MoQ Transport [moqt] track carries DEFLATE-compressed payloads. Each subgroup is one raw DEFLATE stream, sync flushed at each object boundary, so every object stays self-delimited while later objects compress against the earlier ones in the subgroup. Small repetitive payloads compress several times better than they do alone, and a dropped group costs nothing beyond itself because the window never spans one. Nothing is added to the wire: the application declares the track compressed, and a relay forwards it unchanged.