In my opinion, one of the most powerful, yet underused, discovery devices around is the corporate representative deposition. This is because whomever is selected as the representative bonds the corporate entity with whatever their answers are. They are not testifying based solely upon their personal knowledge, but based upon all information known or available to the corporate entity.
That is the reason that the notice of the deposition must list the topic areas to be addressed- so that the corporation can select an appropriate designee who will be prepared to testify as to each of the topics. 
I am usually taking corporate representative depositions in limited categories of industries: trucking, bus or taxi companies, other entities that employed a driver involved in a collision, or representatives of insurance companies. What I have found is that often the individuals produced to testify either have not been properly prepared by counsel, or they have not taken steps to familiarize themselves with the topic list, or have not made a search for the documents that I have demanded be produced. So here are a few ways to make sure that favorable responses to questions based on those failures will hold up and be admitted when you try to use them:
First, in the preliminary instruction portion of the deposition, I ask the following questions:
You understand that you are here to testify on behalf of XYZ Corporation?
You understand that your answers will be based not only on your personal knowledge, but also based upon all information that is known to or available to the corporation?
You understand that your answers today will be binding on XYZ Corporation?
Then I take the Notice of Deposition and mark it as Exhibit 1.
Mr. Representative, can you take a look at what I have marked as Exhibit 1, which is a copy of the notice for this deposition?
Have you ever seen Exhibit 1 before?
Have you read it before today?
Are you prepared today to give testimony about each of the subject areas that appear in Attachment 1, the Topic List?
If you will turn to the next page, you will see Attachment 2, which is a list of documents that I have asked you to produce.
Have you seen Attachment 2 before? When? Have you read it? Have you made an effort to search for responsive documents?
Then I go through the list of categories of documents. I read each request and ask the following for each category:
Do you have any documents to produce today in response to category 1? What?
Are there any documents that you are not producing today? What?
Why are they not being produced? If it’s a privilege issue, ask sufficient follow-up to be able to test the privilege. What is the document, who has possession of it, what is the date and what general topic does it address?
If they say there are no documents responsive to a particular request, ask: Have you made a diligent search in advance of this deposition for documents responsive to that request?
After that series of questions, you can go ahead and ask anything you like with reasonable confidence that you will be able to use it against the entity at trial, and they will not succeed in wiggling out of any answers they don’t like later on. And you will most likely get a ton of good stuff, because for some reason it seems like corporate representatives are never fully prepared, and even after you tell them in advance, they don’t appreciate the binding legal effect their answers will have. Just about every time I do this, I get useful binding concessions, and I bet you will too.
