An interesting article which talks about traceablity and use cases.
From the Article
How can requirements be traced to use cases? This is a simple question, yet opens up the question of how requirements are expressed as use cases.
Requirements (or "high level requirements") are nothing more than a Christmas wish-list of user’s wants. In the professional world, most requirements are not clearly stated. Requirements are often written as large paragraphs of text. Recommended is to take the written paragraphs underlining "requirements statements" and give each one a numerical identifier.
Worth Reading …