The tick that this message was sent on.
Index of the player that this message belongs to.
Command sequence number
Server tick, tends to deviate from NetSvcMessage.NetTick.tick by up to 2 ticks or so.
Player view angles (pitch, yaw, roll) in degrees.
Player movement impulse (forward, sideways, vertical).
2D vector of raw mouse movement deltas.
Button flags. See here for a list of possible values.
If nonzero, entindex of the entity that was just picked up. Doesn't seem to catch every pickup, though.
If nonzero, entindex of the portal through which an entity was picked up.
(Number of?) predicted portal teleportations. Doesn't seem to ever actually appear?
Selected weapon index (irrelevant for Portal 2).
Selected weapon subtype index (irrelevant for Portal 2).
Pending acknowledgements of this message.
Contains the player's inputs and information about certain in-game actions.