[Gardener2]

I think that a Waiting For task would logically be on hold if it's not your responsibility to get the project moving again.

For example, maybe your boss asked you to prepare a document and you gave him the first draft. You know that eventually he'll get back to you with changes, but you know from experience that he'll get back to you when he gets back to you, and that nagging him is just going to annoy him. So you put the "Waiting For" action in the project as a placeholder to tell you why that project isn't in progress, but it's not your job to get the project moving again - it will move when your boss gets back to you.

This is the only kind of thing that I use Waiting For for. If it's _my_ responsibility to get the project moving, I instead create a "follow up" action with a future start date.

Gardener

Edited to add: You could also reasonably use an On Hold Waiting For action if you have complete confidence that you'll evaluate and perhaps change that On Hold status in a timely manner, for example in your weekly review. That way, it's out of your way during your everyday work, but you know that you'll activate it before it gets too stale. I don't have that complete confidence.