Newly observed domain category

Hi,

At the moment we are getting a high influx of webfilter blocks for newly observed domain.

While looking for info about the category all i could really find was: "Newly observed domain (NOD) applies to URLs whose domain name is not rated and were observed for the first time in the past 30 minutes".

Are these being actively rated by FortiGuard or do they wait untill someone submits the domain for review on fortiguard?

Because if these are not actively updated I only see options:

- allow the NOD category(not recommended since it's a risk)

- submit a review any time one of these comes in (work intensive)

Any info would be greatly appreciated.