IANA reserved Address Space

[<Brennan_Murphy () NAI com>]

I'm tasked with coming up with an IP plan for an very large lab
network. I want to maximize route table manageability and
router/firewall log readability. I was thinking of building this
lab with the following address space:

1.0.0.0 /8
10.0.0.0 /8
100.0.0.0 /8

I need 3 distinct zones which is why I wanted to separate
them out. In any case, I was wondering about the
status of the 1 /8 and the 100 /8 networks. What does
it mean that they are IANA reserved? Reserved for what?
http://www.iana.org/assignments/ipv4-address-space

Anyone else ever use IANA reserved address spacing for
lab networks? Is there anything special I need to know?
I'm under the impression that as long as I stay away
from special use address space, I've got no worries.
http://www.rfc-editor.org/rfc/rfc3330.txt

Thanks,
BM