create a document using Word

Hello,
I would like to use Word to create a document on a product.
This product is for two clients. It includes a global architecture, and contains some details for the client A and other information to the client B.
I therefore wish to have a single document at me (which I do to maintain two days), but without the customer can track a customer's information B (and vice versa).
Thus, the solution tagged areas A, B or town would be a good idea but I do not know if this is possible in Word or a plugin!
Thank you for your help

Why not use the tools menu in the comparison and fusion.
you create a word doc to the customer and one word doc to the client B
doc and a A & B, which will make the changes reflected in the document A and B

In fact, my goal was to have a single document and avoid fusion of several versions of files A or B or global ... I think my idea is not possible :(

You tried to format> font> hidden?

Otherwise, I do not know how to present your document, or how many parties "optional" as you, but word is it possible to print only certain sections.
So by spreading your breaks wisely section depending on the content, you may be able to get there.