-Zebra Protocol is a streaming protocol, with a common header. Two
-versions of the header are in use. Version 0 is implicitely versioned.
-Version 1 has an explicit version field. Version 0 can be distinguished
-from all other versions by examining the 3rd byte of the header, which
-contains a marker value for all versions bar version 0. The marker byte
-corresponds to the command field in version 0, and the marker value is
-a reserved command in version 0.
-
-We do not anticipate there will be further versions of the header for
-the foreseeable future, as the command field in version 1 is wide
-enough to allow for future extensions to done compatibly through
-seperate commands.
+Zebra Protocol is a streaming protocol, with a common header. The protocol
+is versioned to allow for incompatible changes. Version 0 is implicitely
+versioned. Version 1 onwards has an explicit version field. Version 0 can
+be distinguished from all other versions by examining the 3rd byte of the
+header, which contains a marker value of 255 for all versions bar version 0.
+The marker byte corresponds to the command field in version 0, and the
+marker value is a reserved command in version 0.