Unknown values in sources

[/dev/not/null]

Sometimes I meets in different wowcore sources something like "unknown value". This value exists in packets. What is it ?

[Talendrys]

It's unknown. 

[antz]

To clarify this further....

There are situations where we know the packet is a certain size but we don't know the meaning of everything in the packet.... i.e.

Packet is 8 bytes long
0-1 Id Field
2-5 Size of object
6 Allegiance Flag
7-8 Unknown