Field Name	Field Notes
Block Definition	Map of block states. { key (component name):[label,value] } (Can be left empty.)
Item Info	See: ItemData Type
Multiplayer Correlation Id	A UUID to identify this multiplayer session.
Enable Item Stack Net Manager	Whether the new item stack net manager is enabled for server authoritative inventory. This will eventually be required.
Server version	For telemetry purposes - sending your own string with your own server name and version here would be useful for Mojang's telemetry.
Player Property Data	like SyncActorPropertyPacket, specifically for minecraft:player properties
Server Block Type Registry Checksum	Checksum for detecting mismatches in block types between server and client.
Server Enabled ClientSide Generation	BiomeComponentFactory needs to know about this toggle before we start parsing BiomeComponents