offset 63 or 0 for disklabel/fdisk?

[Sven Kirmess <Sven_(_dot_)_Kirmess_(_at_)_gmx_(_dot_)_net>]

I guess that's a FAQ and I am sorry about asking this but I could not
find the answer.

When I give the whole disk to OpenBSD during the installation it
creates a partition like this:

*3: A6    0   1   1 -  262 254  63 [        63 -    4225032] OpenBSD

Why does it not create a partition like starting at head 0 or why does
it leave the first 64 (0 - 63) blocks free? Are they all used for the
MBR?


In the manpage of fdisk (3.0) we have an example like this:

*0: A6    0   0   1 -   79   1  18 [         0 -       2880] OpenBSD

Is this valid (starting at head 0)?


Sven