-- Server
function SendIDs( ToPlayer )

	umsg.Start( "PlayerIDs", ToPlayer ) -- First we start the umsg.  The first argument is the name, the seocnd is the filter (See Recipient Filter)
  	
		umsg.Short( #player.GetAll( ) ) -- Since we don't read it as a table, we need to know how many values we have.
		
		for i, v in pairs( player.GetAll( ) ) do
		
			umsg.String( v:UniqueID( ) ) -- Now we send our Steam IDs
		
		end
	
 	umsg.End( ) -- Now we end our umsg.  It will now be streamed to the client

end

-- Client
function ReadIDs( umsg )

	local Count = umsg:ReadShort( ) -- This is the number of Steam IDs we set on line 6
	local SteamIDs = { } -- We'll store the SteamIDs in here
	
	for i = 1, Count do
	
		SteamIDs[ i ] = umsg:ReadString( )
	
	end
	
	-- You're done.

end
usermessage.Hook( "PlayerIDs", ReadIDs )