Acknowledgments

The authors thank Rich Salz for the expert review on the "co" ALPN ID allocation.

They also thank Mohamed Boucadair and Ben Schwartz for early reviews before WG adoption, and Esko Dijk, Thomas Fossati, and Marco Tiloca for feedback and comments.

This work was supported in part by the German Federal Ministry of Research, Technology, and Space (BMFTR) through the PIVOT and C-ray4edge research projects.