Vern -
I agree that a Task Order is a contract but there are places in the FAR, specifically 16.504 where the two terms have very distinct meanings and some folks want to use them interchangeably. I do assisted acquisitions and have had the conversation multiple times that yes you can award a single TO for over $100M without getting head of agency approval because the multiple award preference paragraph is referring to the IDIQ, not the task orders under the IDIQ.
As for the other, I meant to state sole-source versus single award. Sorry for the confusion. In the background of the DFARS case I cited, the write-up referred several times to a prohibition on sole-source IDIQs when they really meant single award IDIQs. Guess I should have read what I wrote more carefully to ensure it said what I meant.