Rule 26 covers initial disclosure of sources of discoverable information, as well as sources of information that are not discoverable due to undue burden or cost. Obviously, IT has a huge role to play here.

Rule 26 requires both parties to disclose all information that is relevant to either their claim or defense. The parties must identify information by category and location, Zantaz's Lambert notes. If pertinent data is not disclosed up front, it may not be admissible later.

However, the more interesting part of Rule 26 is (b) (2) [B], if only because interpretation of it may change depending on the case at hand. For instance, if a lawsuit is for $150,000, it may not behoove the judge to force a company to spend $2 million accessing hard-to-retrieve data that exists only on legacy disaster-recovery tapes. However, if the case involves a $50 million lawsuit it could be another matter altogether.

This means a company should have a pretty good idea how much it will cost to restore data from various media, file types, and locations. The tricky part is that before you know how much it will cost to retrieve the data, you must know which data is stored where.

The solution lies in mapping your data sources. This should be a joint effort between legal and IT, PSS's Paknad says. But mapping data sources is easier said than done. For one thing, it assumes that someone in the company knows what data is relevant and where it all is. In a large company, this may be a wholly unwarranted assumption.