gmirror, gpart and MBR vs GPT in the Handbook

[Mike.]

Hi,

The Handbook page about creating a gmirror array 
(
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/geom-mi
rror.html )
has the command:

	gpart create -s MBR mirror/gm0

I've read elsewhere in the handbook that GPT is preferrable to
the older and less versatile MBR scheme.  

Is there a specific reason why MBR was used in the Handbook
example for creating a mirror, instead of GPT?   Or was it just
a preference of the person who wrote that Handbook page?

Thanks,
Mike.