The document discusses product data sheets, which some see as technical documents but others view as marketing materials. It notes that producing data sheets is a major responsibility for many marketing managers. The author received over 10,000 words of feedback from readers on what should be included in data sheets and how they should be presented. The article will be the first in a series discussing data sheets in more detail over several weeks. It considers how data sheets fit within a company's literature hierarchy and debates whether they should focus on product features for existing customers or benefits for potential buyers.