This means you will be able to use it, but you really shouldn't.
Used internally by net.WriteTable.
Appends any type of value to the current net message.
An additional 8-bit unsigned integer indicating the type will automatically be written to the packet before the value, in order to facilitate reading with net.ReadType. If you know the data type you are writing, use a function meant for that specific data type to reduce amount of data sent.