How to mark-up a question?

Dear list,

at the moment I am writing a statement of work (german Lastenheft) and 
there are some open points I cannot answer at the moment. I would like 
to include theses questions in the document I am writing but I don't 
know how mark them up?

My goal is to have the following in the output documents:

Questions
Question 1: Is it possible to have xyz.
Question 2: Does we need abc?
Question 3: ....


Regards,

Oliver Fischer