Statement about priorities

Somewhere on David's site I've found the following statement about priorities:

- focus on something important
- refocus on interruptions as they come up
- handle volumes of unclarity
- reprioritize based on changing data
- and ... stay sane at the same time.

I can't get what is meant by "handle volumes of unclarity". Any ideas what it means in the terms of prioritization?

I assume it means the ability to make smart decisions about large volumes of incoming, unclear stuff. With GTD--or a similar system--you don't get overwhelmed when you receive a lot of vague stuff to process.