domain.local, _msdcs.domain.local and the delegation for _msdcs.domain.local under domain.local

Gurus,

I have studied MS Windows 2000 and 2003 for a couple of years now. I am
slow to get my head wrapped around certain things though. As I
understand it, in MS Windows 2000+ DNS, you basically have two main zones.

domain.local
_msdcs.domain.local

Here is my point-by-point understanding of these zones, and correct me if
I'm wrong.

1) domain.local is the obvious one. That contains all the host , SRV
records and sites locations for the AD domain.
2) _msdcs.domain.local zone contains the records of all the Global Catalogs
and all domains in the entire forest. This is essentially the forest root
domain.
3) Finally, there is the delegation for _msdcs.domain.local in the
domain.local zone. This delegation zone contains NS records that point to
the _msdcs.domain.local - which again is basically the forest root domain.

So am I right or wrong?