Task / Milestone status like GTD

Task / Milestone status like GTD

in my company, often there are tasks or milestones that are waiting for a customer response (usually some kind of approval) before we can proceed.

Previously we used a GTD (Getting Things Done) style of "Waiting for" context for the task in question.

Is there some way to do the same thing in Projects? Right now we're using pretty general tasks like "Production"